Hi, I'm Gami and this is my Pioneer Soulflayer list! If you want to play an interactive, unique graveyard combo deck, you're in the right place!
This deck is built to maximise the power of Soulflayer and Urborg Scavengers to apply early pressure with a hard to remove threat while disrupting its opponents for long enough to win.

Deck Info:

>Noteable Inclusions:

Boseiju, Who Endures – The manabase has been one of the most difficult things about building this deck and while Boseiju hardly counts as a land as it casts very few of our spells, having a maindeck way to remove problem enchantments has been invaluable. In my testing it has saved more games than it’s ruined, but it has ruined games. Being the only land in the deck that doesn’t make B for Soulflayer on turn 2 or not being able to cast a second spell as the colours aren’t right is a real problem, but it’s a problem that can be played around if you’re aware that it might come up.

Malcolm, Alluring Scoundrel – I was initially low on this card, but I feel that it plays a lot better than it may first appear. Flash means it almost always connects once unless they hold up instant speed removal to play around it and when the rest of our deck is so non-creature based that’s often the incorrect thing to do. If it deals combat damage four times, we can start using it to cast spells for free, including Zetalpa and Samut. This is another plan to get around graveyard hate that we can play in the maindeck.

Samut, Voice of Dissent - This deck is less all-in on creatures for Soulflayer to delve than most, only having seven main exile targets. Zetapla is standard, Samut less so. The reason why, is that almost any combination of Samut and another creature, is powerful, where other options needed three to four different creatures to have been milled to be a real threat without Zetalpa. This means we can run fewer threats overall and have much higher card quality.
Bitter Triumph - A card that interacts with the opponent while also furthering our gameplan. A fantastic way to convert dead cards into value.

Deep-Cavern Bat – Flying, lifelink and hand disruption are all things that this deck wants. I wish it didn’t add to the already quite large two-drop slot, but it’s been an invaluable tool against control, combo and aggro decks. This is the reason the deck is only running two Thoughtseize.

Extract the Truth – Since Leyline of the Void is such a blowout, when we even slightly suspect that an opponent will play it, we have to be prepared. This is a card that we can bring in if we suspect Leyline, but then won’t be completely dead if they don’t have it. On the surface, this seems terrible, but answering a Leyline for two mana while also having relevant text if not needed for that is fantastic. The floor is a bad Duress, the ceiling is dealing with a card that completely stops our gameplan.

>Noteable Exclusions:

Banehound - Blocking vs aggressive decks and/or forcing opponents to trade into these is very strong, especially when we don't mind if it dies. But when it’s a card that fundamentally doesn’t further our gameplan aside from maybe chump blocking and being exiled later I feel we can play better cards. I think with Deep-Cavern Bat being printed I’d be very surprised if I register Banehound again.

Ledger Shredder - Shredder can block vs aggro and get damage in against control, all while forcing our opponents to think about how many spells they're casting and furthering or gameplan, which sounds fantastic! However, when you need to double spell to do so on an already restrictive manabase, in a deck that need to run a non-zero number of uncastable cards, that can be more difficult that it sounds. I found more often than not; Shredder didn’t let me discard a key card because I couldn’t cast a second spell early game. With the printing of Malcolm, Alluring Scoundrel, Bitter Triumph and running more copies of Tainted Indulgence, I think that the deck can be more consistent at discarding its cards, without having to worry so much about the mana curve and the amount of one drops. Shredder is undoubtedly powerful, but I feel it was getting to the point where it was restricting the deck more than it was helping it.

Cragplate Baloth - Hexproof and haste is fine, but only good as the first Urborg Scavengers target, even then, Scavengers can still be removed in response.

Adult Gold Dragon - A similar story, extra lifelink is good, but I don't think it's better than Samut.

Neoform / Atraxa, Grand Unifier - There's an argument that the Atraxa Neoform variant is a better deck, but I think we can be equally consistent, if not more so, and pose a bigger, harder to remove threat, even if it doesn't refill our hand.

Founding the Third Path - I like this card a lot for its ability to pseudo colour fix, mill and reuse spells from the graveyard, a lot of what the deck wants to do. But there's one issue, we want to do as much as we can at instant speed, a non-creature sorcery speed spell that doesn’t offer any selection isn't where we want to be in this deck. It’s more suited to something like Neo-Atraxa where it can flashback Neoform and trigger revolt for Fatal Push.

Lands - Nineteen is low, but when the most expensive card we're trying to cast in the deck is Urborg Scavengers at three mana and we have 19 ways to filter and draw cards at two mana or less, we can run a comparatively low number of lands while still being consistent. One or two land hands are perfectly keepable if they have one or two dig spells.
If we take into account the mana we actually intend to pay for each card, Soulflayer being BB, Striped Riverwinder being U etc. the average mana value of the maindeck is 1.79. Using Frank Karsten's fairly well respected method for calculating the minimum number of lands needed in a deck, that being 19.59 + (1.90 * average cmc) – (0.28 * cheap card selection spells), we get 19.59 + (1.90 * 1.79) – (0.28 * 19) = 17.67 lands, even discounting Boseiju, Who Endures as a land still gets us comfortably over this guideline, so hopefully that gives you some confidence!

>Currently Testing:

Ashiok, Dream Render - Lotus will fold to this, as will most of the big mana Bring to Light or Enigmatic Incarnation decks. Three mana is relatively expensive for this deck, but this will absolutely win games when it resolves.

Knight of Dusk’s Shadow / Weathered Runestone – Both of these are to combat the rapidly rising Amalia combo deck that wins by gaining huge amounts of life and cheating creatures into play with Chord of Calling and Collected Company. Runestone also has some equity against Arclight Phoenix, Enigmatic Fires and Greasefang.

Sideboard Theory:

> Rakdos (Midrange / Aggro / Sacrifice):

There are three main types of Rakdos decks in Pioneer now, Midrange, Aggro and Sacrifice. Midrange is the deck you’re probably most familiar with, Sheoldred, the Apocalypse, Bonecrusher Giant etc. slower, but more inevitable. Aggro forgoes this late game inevitability by trying to go faster with Smuggler’s Copter, Inti, Seneschal of the Sun and more one drop threats. Sacrifice is the most different, playing Mayhem Devil and the Witch’s Oven, Cauldron Familiar loop.

Their Problem Cards:

Graveyard Exile – Go Blank, Hidetsugu Consumes All, Unlicensed Hearse, Leyline of the Void
Soulflayer Removal - Extinction Event, Languish, Liliana of the Veil, Sheoldred’s Edict
Threats – Sheoldred, the Apocalypse, Archfiend of the Dross

Game One:

All three of these matchups are favoured for us, their only relevant interaction mainboard across all decks is Graveyard Trespasser, Bloodtithe Harvester because it gets around indestructible and the ever-present Thoughtseize. Sorcery speed interaction is fairly simple to play around, so game one shouldn’t be too much of a challenge.

Post-Board:

A little harder as any number of hate cards come in, most harmful being Leyline of the Void that all three versions can play. Be careful if they reveal Jegantha, the Wellspring game one but not game two, this means they likely have brought in Leyline.
Gameplan is mostly the same, but this time we can answer their board a little more efficiently and have to play around graveyard hate.

Changes:

In:
2x Extract the Truth – Can do a bad Duress impression at its floor or remove a Leyline that they thought we’d just lose to.
1x Assassin's Trophy - Can remove Sheoldred, the Apocalypse, Archfiend, Leyline or any other problem permanent. Gives them a land, but a land should always be much less scary than the thing it removes.
1x Haywire Mite - Kills Leyline of the Void if they have it, otherwise it can hit other graveyard hate or Fable of the Mirror Breaker.
1x Stubborn Denial – Catches early copies of Fable, Liliana, Go Blank etc. and can hard counter an Extinction Event or Languish late game.

Out:
2x Thoughtseize - While hand disruption is good, it's a terrible draw when both players are low on resources, the Deep-Cavern Bats are at least 1/1 fliers in a topdeck situation.
2x Otherworldly Gaze - Going down on cards in the matchup where resources will be precious isn't great. We'd like a higher card quality going in this matchup and can afford to go slightly slower.
1x Striped Riverwinder – While is seems wrong to trim a Riverwinder against the removal deck, a lot of their removal is instant speed, meaning even if we go to exile a Riverwinder with Scavangers they can respond and kill it, destruction-based so if we have Zetalpa it doesn’t work anyway, or completely ignores any protection we could have had. Trimming one for more interactive cards feels safe.

>Phoenix (Izzet / Grixis):

Phoenix has risen from the ashes with the printing of Picklock Prankster and a Grixis version has sprung up because of Bitter Triumph, this version has an almost completely Dimir manabase, playing cards like Sheoldred, the Apocalypse, Fatal Push and Thoughtseize alongside the typical Phoenix cards of cantrips and Treasure Cruise.

Their Problem Cards:

Soulflayer Removal – Brazen Borrowe, Languish
Creature Counterspells – Disdainful Stroke
Graveyard Exile – Go Blank
Extraction Effects - Unmoored Ego

Changes:

In:
3x Mystical Dispute - Will hit all their counters and most of their creatures, though the best target for it is Treasure Cruise.
1x Weathered Runestone – Stops Arclight Phoenix coming back from the graveyard. They can still play around this by hardcasting them, but it’s not where the deck wants to be.
1x Ashiok, Dream Render - Incidentally exiling their graveyard is a great effect to have access to.

Out:
3x Malcolm, Alluring Scoundrel – The deck is full of fliers, so Malcolm won’t be able to deal damage consistently.
2x Thoughtseize – They’re a very resilient deck with all their card filtering. One of the few important cards you would take actively wants to be discarded. Thoughtseize doesn’t help in this matchup.

>Abzan Amalia:

Amalia is the newest combo deck in Pioneer and it’s very strong, a fast combo that can be put into play at instant speed with Chord of Calling or Collected Company and has redundancy with Return to the Ranks.

Their Problem Cards:

Threats - Amalia Benavides Aguirre, Wildgrowth Walker
Graveyard Exile – Jirina, Dauntless General, Leyline of the Void

Changes:

In:
3x Path of Peril – Removes 90% of their creatures.
2x Extract the Truth – Can hit Leyline or discard key combo pieces.
1x Weathered Runestone – Stops CoCo and Chord of Calling
1x Knight of Dusk’s Shadow – Shuts down their combo, they will have to remove this before they can kill us.

Out:
3x Malcolm, Alluring Scoundrel – They have too many incidental fliers for Malcolm to be as consistent as we want, between Deep-Cavern Bat, Archon of Emeria and Gilded Goose they have plenty of ways to block.
2x Striped Riverwinder – Even post-board they have absolutely no way to remove a Soulflayer and only Fatal Push with revolt to remove a Scavenger, can cut two here.
2x Tainted Indulgence – In the faster matchups, the slowest enablers come out. Be aware that you’ve cut a lot of ways to discard cards here, so hands with uncastable delve targets are much less keepable than usual.

> Azorius Control:

Control will be a slower game and is a difficult matchup, although they play fewer true counterspells than they used to and their build is much more aggressive. This favours us, as the way they win is to stabilize in the late game and overwhelm us, the most recent builds are worse at doing this, prioritizing early game over late game power due to the presence of Amalia Combo.

Their Problem Cards:

Graveyard Hate – Farewell, Rest in Peace
Soulflayer Removal - Farewell
Creature Counterspells – Absorb, Make Disappear

Game One:

Take your time, don't rush. Force them to use their interaction on less important things. If you suspect they have a counterspell and have the option, cast Scavengers first, as if it gets countered you still have cards in graveyard to use. Cast instants when/if they tap out on your end step. This is not a race.
Don't be afraid to cast Urborg Scavengers early with no value if you think you can get them to resolve and start getting damage in. If you can start exiling relevant things as well, even better.

Post-Board:

Rest in Peace absolutely destroys our gameplan, so try to always have hand disruption or counters for it. Other than that, very similar to Game One but we have more disruption and they have Rest in Peace.

Changes:

In:
3x Mystical Dispute - Interacting efficiently is key, hitting Memory Deluge or resolving something through an Absorb is great.
1x Stubborn Denial – Will hit Rest in Peace early game or counter a Farewell that would kill our threat.
1x Disdainful Stroke – Counters any big, expensive play they make.
1x Assassin’s Trophy – Removes RiP or another problem permanent they’ve managed to resolve.

Out:
2x Otherworldly Gaze – Card efficiency will be relevant here. Gaze going down a card, even though it sees six over the course of the game, means it’s a worse spell in this matchup, trimmed two.
2x Malcolm, Alluring Scoundrel – Since this will be a longer game and Malcolm is legendary, drawing a second while the other is still on board isn’t great, they can also make 1/1 sharks at instant speed to remove him and deny us the card filtering. Slightly too vulnerable here.
1x Samut, Voice of Dissent – Since the game will go longer than most, we can cut down on a few delve targets as we have more time to find them.
1x Striped Riverwinder – The only targeted removal is Get Lost, Teferi, Hero of Dominaria, The Wandering Emperor and March of Otherwordly Light. Indestructible stops Get Lost and March will be quite expensive as it’s based on mana cost. The Wandering Emperor gets stopped by vigilance as the creature will never be tapped. As well as this we’re bringing in 5 disruptive spells. I feel comfortable trimming one Riverwinder here.

>Boros Convoke:

Their Problem Cards:

Threats - Gleeful Demolition, Venerated Loxodon, Reckless
Spell Tax – Thalia, Guardian of Thraben
Graveyard Exile – Rest in Peace

Changes:

In:
3x Path of Peril - Wipes all their smaller tokens and lets us stabilise.
1x Haywire Mite – Removes Rest in Peace and gains us a small amount of life if it dies.

Out:
2x Thoughtseize – While Thoughtseize can disrupt their most aggressive starts, it’s next to useless outside of that as it’ll lose us more life than the disruption is worth.
1x Tainted Indulgence – Faster matchups want more efficient ways to fill the graveyard.
1x Striped Riverwinder - Next to no removal in their deck. A Giant Killer is all that we need to worry about.

> Lotus Combo:

Lotus can be fast, but often stumbles if it’s interacted with. We have six maindeck discard spells, so the matchup should be good if we open with one of them. Their combo revolves around looping Chandra, Hope’s Beacon with three copies of Bala Ged Recovery, if you can exile one or more of these from their graveyard over the course of the game with Scavengers, it makes it harder for them to combo.

Their Problem Cards:

Threats - Lotus Field, Emergent Ultimatum
Soulflayer Removal – Languish, Sunfall

Game One:

Thoughtsieze their hand, apply pressure. We have relatively few ways to deal with their combo other than simply to discard the pieces of it.

Post-Board:

Better, as we have more disruption, but the same still applies. Pressure wins games here.

Changes:

In:
3x Mystical Dispute - Catches a lot of important spells, most notably Emergent Ultimatum and Pore Over the Pages.
1x Disdainful Stroke – Counters almost all their big impactful plays.
1x Ashiok, Dream Render - Difficult to remove. Their passive ability is very disruptive and their -1 incidentally exiling their graveyard makes things harder too.

Out:
2x Striped Riverwinder – Next to no targeted removal coming from Lotus so we can get away with fewer copies of hexproof.
2x Bitter Triumph – While this does remove Chandra while they’re comboing if they’ve got to that point, we’re likely already losing and it has few other relevant targets.
1x Tainted Indulgence - Only putting one card in the graveyard is the slowest of our dig spells. The longer the game goes, the more likely they are to combo, so the slowest enablers come out.

> Gruul Midrange:

Gruul has picked up Smugglers Copter to lower their curve and be more aggressive They have artifacts, enchantments and creatures as a way to pressure you so one set of removal isn’t going to work as well as it once did. As well as this, they are very heavy on three drops, so Path of Peril is terrible against them, this has the potential to be one of our worst matchups if we run badly.

Their Problem Cards:

Soulflayer Removal - The Akroan War
Graveyard Exile - Klothys, God of Destiny, Unlicensed Hearse, Tranquil Frillback

Changes:

In:
1x Assassin's Trophy – Mostly for The Akroan War or Esika’s Chariot, but can also remove graveyard hate and any creature.
1x Haywire Mite - We have to use this in response to them crewing a vehicle, as it specifies non-creature, but can really swing the tempo back in our favour.
1x Stubborn Denial – Has the potential to catch some of their early game spells and become Negate once a Soulflayer has resolved.

Out:
2x Thoughtseize - They're a very resilient deck, so throwing away a card isn't as impactful.
1x Malcolm, Alluring Scoundrel – Malcolm is great unless they have Smuggler’s Copter in which case he’s basically a dead card. Trimmed one.

>Five-Colour Fires:

Their Problem Cards:

Threats - Fires of Invention, Enigmatic Incarnation
Graveyard Exile - Rest in Peace, Leyline of the Void, Kutzil’s Flanker
Soulflayer Removal – Chained to the Rocks, Leyline Binding, Deputy of Detention etc.

Changes:

In:
1x Assassin's Trophy - Kills the bigger threats if they have time to stabilise or Leyline of the Void if they try to stop us early.
1x Haywire Mite - Removes all their enchantments.
1x Ashiok, Dream Render – Stops Incarnation completely. Weathered Runestone also does this, but doesn’t further our gameplan. The later this matchup goes, the worse it is for us, they’re better equipped for the endgame than we are.
1x Disdainful Stroke – Counters both their engines and Leyline Binding.

Out:
2x Tainted Indulgence – We need to go as fast as possible to outrace them, only putting on card in graveyard at a time isn’t going to do that.
2x Thoughtseize – While hand disruption is good, they’re designed to go over the top of it. Deep-Caven Bats stay in as they at least present a clock if unanswered.

>Abzan Greasefang:

Greasefang is a smaller part of the meta as there’s more graveyard hate than usual, and a lot of players switched to Amalia Combo as the manabases are very similar. That doesn’t mean the deck is bad, it’s still just as strong as it once was if you don’t have to right tools to beat it.

Their Problem Cards:

Threats - Greasefang, Okiba Boss, Parhelion II
Graveyard Exile – Kutzil’s Flanke, Go Blank, Unlicenced Hearse

Game One:

Getting a strong Soulflayer is borderline game over. Both decks combo at similar speeds, but we have seven threats and they only have four, some are running six if you count Eldritch Evolution or Traverse the Ulvenwald, but these take much more time than the dreaded turn three Greasefang.

Post-Board:

They have more interaction post-board, be aware of all the ways they can exile your graveyard, especially Kutzil’s Flanker, which can happen at instant speed.
We get more hate and interaction too, so the dynamic of the match doesn’t change much.

Changes:

In:
1x Ashiok, Dream Render - Hard for them to remove and repeatedly exiles their graveyard. They'll have to combo all in one turn to dodge us exiling Parhelion.
1x Haywire Mite - Kills vehicles in response to them crewing. Be careful to sacrifice it in response to the crew trigger as Mite specifies a non-creature artifact. If you try before, they can crew it in response, making it no longer a legal target.
1x Assassin's Trophy - Destroys any permanent, no questions asked, Usually Greasefang or Parhelion, but also hits Leyline of the Void if they're running it.
1x Weathered Runestone – Completely stops Parhelion II being reanimated. They have plenty of answers for this, but it’s a roadblock they need to overcome to win.

Out:
2x Tainted Indulgence – Speed is important here so only putting one card in graveyard is a little too slow.
2x Striped Riverwinder - They have relatively little targeted removal, so two copies can come out.

If you see Leyline of the Void:

In:
2x Extract the Truth – Leyline completely shuts down our gameplan, so we bring in as many answers as possible.
Out:
2x Deep-Cavern Bat – While lifelink is nice, it’s one of the least impactful effects in the deck in this matchup. Cavern Bat is a Thoughtseize that happens to come attached to a flying lifelink creature and we’re trading it for one that comes attached to enchantment removal.

>Mono-White Humans:

Mono-white seems like it should be an easy matchup on the surface, but it’s very much a race. They can’t beat a hexproof doublestrike Soulflayer, but they won’t give us much time to set up at all. Thalia, Guardian of Thraben is one of our worst nightmares as her one mana tax is incredibly stifling. Discard her or remove her as your top priority.

Their Problem Cards:

Graveyard Exile - Rest in Peace
Spell Tax - Thalia, Guardian of Thraben

Game One:

As simple as Aggro vs Combo gets, aim to cast Soulflayer before they kill you.

Post-Board:

The matchup gets quite a bit better with plenty of sideboard cards in, prioritize lifelink and hexproof to make an impossible to remove Soulflayer as soon as possible.

Changes:

In:
3x Path of Peril – A wrath on turn three or four typically sets them back long enough for us to win.
1x Haywire Mite – A way to remove Rest in Peace and can also help our life total when it dies.

Out:
2x Thoughtseize - Hand interaction is much less important in the aggro matchup, losing two life is also relevant.
2x Tainted Indulgence – Humans won’t be a grind, so the slowest ways to fill the graveyard come out.

>Mono-Red Aggro:

They will be fast, but have literally no way to remove a resolved Soulflayer, if we get indestructible and lifelink, it's basically game over. Some lists are maindecking Rampaging Ferocidons to stop lifegain from Amalia, this also indirectly hurts us as we usually try and stabilise on a low life total and use lifelink to get back into the game. Save your removal for this if you can.

Their Problem Cards:

Soulflayer Removal – Roast
Threats – Ojer Axonil, Deepest Might, Eidolon of the Great Revel
Graveyard Exile – Unlicensed Hearse
Lifegain Hate – Rampaging Ferocidons

Game One:

This is simply a race, force them to direct burn spells at your creatures rather than your face, get lifelink as soon as you can. Win from there.

Post-Board:

Very similar, but we have more disruption, eight damage a turn is hard to race, especially if they're losing attackers running into a Soulflayer with vigilance.

Changes:

In:
3x Path of Peril - Can be used to come back from the jaws of defeat.
1x Haywire Mite - Blocking a large attacker and gaining two life is surprisingly relevant, can also hit any graveyard hate they may have.

Out:
2x Thoughtseize - The life loss hurts more than the disruption helps.
1x Striped Riverwinder – They need to use multiple burn spells to take out a Soulflayer so hexproof is less relevant.
1x Tainted Indulgence – In the faster matchups, the slowest enablers can get trimmed.

>Lotus Control:

Their Problem Cards:

Soulflayer Removal – Sunfall, Farewell
Graveyard Exile - Rest in Peace

Changes:

In:
3x Mystical Dispute - Interacting efficiently is key, hitting Memory Deluge or resolving something through an Absorb is great.
1x Stubborn Denial – Will hit Rest in Peace early game or counter a Farewell that would kill our threat.
1x Disdainful Stroke – Counters any big, expensive play they make.
1x Assassin’s Trophy – Removes RiP or another problem permanent they’ve managed to resolve.

Out:
3x Malcolm, Alluring Scoundrel – Between 1/1 sharks and 1/3 Strict Proctors, Malcolm just isn’t going to connect as often as we need.
2x Otherworldly Gaze – Card efficiency will be relevant here. Gaze going down a card, even though it sees six over the course of the game, means it’s a worse spell in this matchup, trimmed two.
1x Samut, Voice of Dissent – Since the game will go longer than most, we can cut down on a few delve targets as we have more time to find them.

>Quintorius Combo:

Quintorius Combo is a new one-card combo that aims to win by casting Trumpeting Carnosaur or Quintorius Kand which then uses his Discover 4 ability to find clone effects until his static ability kills the opponent as each one is cast from exile.
This deck completely relies on casting one of it’s two winning spells and without them the deck is pretty terrible. Discard or counter as many as you can and hope to race them.

Their Problem Cards:

Threats – Quintorius Kand, Trumpeting Carnosaur
Soulflayer Removal – Consign//Oblivion, Leyline Binding, Languish, Release to the Wind

Changes:

In:
3x Mystical Dispute
1x Disdainful Stroke

Out:
3x Malcolm, Alluring Scoundrel – Malcolm is a little too slow and dies to Bedeck//Bedazzle and Trumpeting Carnosaur’s discard ability.
1x Tainted Indulgence – Card quality doesn’t matter as much here, it’s a messy race to see who can jam their threat first.

> Selesnya Angels:

Angels is making a comeback as it’s a deck that absolutely flattens Phoenix, low interaction, but an almost insurmountable endgame if they get going.

Their Problem Cards:

Graveyard Exile - Rest in Peace

Changes:

In:
3x Path of Peril –Path isn’t fantastic here, but it clears out any tokens and a lot of their acceleration in the early game. Much later it can be cast for its full cost and wipe everything if we find Mana Confluence.
1x Weathered Runestone – Stops their copies of Collected Company and Kayla’s Reconstruction having any text at all.
1x Knight of Dusk’s Shadow – Turns off all their lifegain, which is the engine of their deck.

Out:
3x Malcolm, Alluring Scoundrel – Their deck is full of fliers so Malcolm will be unlikely to connect consistently.
2x Thoughtseize – Aside from CoCo and Kayla’s Reconstruction, their deck is incredibly resilient, discarding a random Angel is rarely worth a card.

> Nykthos Ramp:

With Karn gone, this deck still exists, but in a much-weakened state. Before, Karn was the decks interaction. With Karn gone, the deck is slower, less consistent and has much fewer ways to remove a threat.

Karn was replaced by Vivien, who can’t wish for a card the turn she comes down, has a more limited set of sideboard options to pick from and needs much more mana to do something impactful.

Their Problem Cards:

Threats – Vivien, Arkbow Ranger, Ulamog the Ceaseless Hunger. Emrakul the Promised End

Game One:

Reasonably straightforward, they have absolutely no way to remove an indestructible-hexproof Soulflayer and aren’t as fast as you are. You should be able to find one good threat and carry it to victory.

Post-Board:

They will have more threats maindeck now, but they still can’t answer ours. Try not to let them snowball value, put on pressure and you should win the match.

Changes:

In:
1x Disdainful Stroke – Counters any of their big plays.
1x Assassin’s Trophy – Removes any threat that they manage to resolve.

Out:
1x Striped Riverwinder – They have incredibly limited removal so hexproof is less important
1x Tainted Indulgence – Only putting one card in the graveyard is the slowest of our dig spells. The longer the game goes, the better their deck gets so the slower spells get trimmed.

>Spirits (Mono-Blue / Azorius / Bant):

Which version of Spirits is the best has been debated for a while, currently Bant and Azorius are about as popular as each other, so be prepared for both. Mono-blue is on the fringes, but much less popular.
The main difference between Azorius and Bant is that bant runs more three drops and Collected Company, making it slightly slower, but more resilient and the cards are more individually powerful. Since it runs CoCo it has to run many more creatures, giving it no space for countermagic.

Their Problem Cards:

Creature Counterspells - Lofty Denial, Geistlight Snare
Graveyard Exile - Rest in Peace, Remorseful Cleric
Soulflayer Removal – Settle the Wreckage

Game One:

As with most aggro decks, they can't beat a resolved Soulflayer with good keywords, they offer similar pressure to other aggro decks and significantly more disruption.
Game one should be relatively straightforward, if difficult. Remove their creatures as much as you can as their counterspells rely on creatures to make them efficient. Don’t be afraid to trade with Deep-Cavern Bat or Malcolm as keeping their board presence low is key.

Post-Board:

Spirits game two is uniquely difficuly, the threat of turn two Rest in Peace, counterspells and a fast clock means that we often want more cards in than we can take out.
Mystical Dispute is great against blue-based decks and Path of Peril is an enormous setback for them, but that leaves us with very few outs to RiP. Be careful though, as even if they’re tapped out Mausoleum Wanderer can counter Path.

Changes:

For All:

In:
3x Mystical Dispute - Will hit most, if not all their spells.
3x Path of Peril – A huge setback, especially since it will make Lofty Denial and Geistlight Snare less efficient.

Out:
3x Malcolm, Alluring Scoundrel – Their entire deck is full of fliers, so Malcolm will rarely be able to attack freely. All copies come out here.
2x Thoughtseize - Their creatures are their card draw, so removing their attackers and Deep-Cavern Bat is our form of resource denial.
1x Striped Riverwinder – They have limited targeted removal outside of Skyclave which only hits Urborg Scavengers.

For Azorius / Bant:

In:
2x Extract the Truth – While I don’t love this here, it’s much better than being cold to Rest in Peace

Out:
2x Tainted Indulgence – In the faster matchups, the slowest enablers come out. Be aware that you’ve cut a lot of ways to discard cards here, so hands with uncastable delve targets are much less keepable than usual.

>Omnath to Light:

Their Problem Cards:

Threats - Bring to Light
Graveyard Exile - Rest in Peace
Soulflayer Removal – Hostage Taker, Valki, God of Lies, Leyline Binding, Chained to the Rocks.
Extraction Effects - Slaughter Games

Changes:

In:
3x Mystical Dispute - Counters Bring To Light and Omnath, worth it just for them.
1x Disdainful Stroke – Counters both their engines and other big plays.
1x Ashiok, Dream Render - Stopping them searching turns off their main value engine.

Out:
3x Malcolm, Alluring Scoundrel – A little too slow and they play Arboreal Grazer which incidentally blocks it forever.
2x Tainted Indulgence – We need to go as fast as possible to outrace them, only putting on card in graveyard at a time isn’t going to do that.

>Mono-Black Midrange:

Mono-Black has the potential to be a horrible matchup for us with maindeck discard, edicts and graveyard hate. Post-board we have to be happy to play without Soulflayer as it’s so difficult for one to stay on board for any length of time.

Their Problem Cards:

Graveyard Exile – Go Blank, Graveyard Tresspasser, Unlicensed Hearse, Cling to Dust, Leyline of the Void.

Soulflayer Removal – Rankles Prank, Sheoldred’s Edict, Liliana of the Veil, Invoke Despair, Extinction Event.

Changes:

In:
2x Extract the Truth – Removes a Leyline from the board or another threat from their hand.
1x Stubborn Denial – Catches early copies of Liliana or Go Blank while countering edicts once we resolve a threat.
1x Haywire Mite – Protects against edicts and can remove Leyline
1x Disdainful Stroke – Counters a lot of their impactful plays like Sheoldred and Invoke Dispair.
1x Assassin’s Trophy – Can remove Leyline as well as any other permanent that is posing a problem.

Out:
2x Zetalpa, Primal Dawn – Not being able to run the Soulflayer plan as we want to means that Zetalpa is a dead card more often than not.
2x Striped Riverwinder – They have next to no targeted removal so we can trim two Riverwinder
1x Soulflayer – The matchup is such a hostile environment for Soulflayer that we often can’t cast it as our graveyard is empty and the opponent has a Liliana to kill it as soon as it resolves. Trimmed one.
1x Samut, Voice of Dissent – As we’re moving slightly away from the Soulflayer plan the mostly uncastable delve spells can be trimmed.

> Creativity (Temur / Izzet):

Temur and Izzet play quite similarly, the biggest tell for which one you’re playing against is that Big Score only appears in Temur and Magma Opus only appears in Izzet. Temur needs to get to five mana and two tokens to flip into Worldspine Wurm and Xenagos, God of Revels to one-shot the opponent. Izzet only needs four and one, but their payoff is much less impactful.
Soulflayer can combo faster than Creativity and then play defense, but there's an element of luck to it, the matchup isn't terrible, but you need to be careful. Either resolve Soulflayer fast and close the game or wait until they're low on resources and capitalise.

Their Problem Cards:

Threats - Indomitable Creativity
Creature Counterspells - Make Disappear, Disdainful Stroke

Game One:

The plan game one is simply to resolve a Soulflayer, doesn't have to be particularly strong or be particularly fast, just make sure it resolves. Deep-Cavern Bat and Thoughtseize should help pave the way for this and to make sure they don’t combo first.

Post-Board:

After boarding it's quite similar but we now have countermagic. They have relatively little to bring in against us so take your time and be ready for a fight on the stack.

Changes:

For Both:

In:
3x Mystical Dispute - More disruption early, hits their counters and makes sure our threats resolve.
1x Disdainful Stroke – This comes in just to counter Indomitable Creativity or Big Score out of Temur.

Out:
3x Malcolm, Alluring Scoundrel – One of their ways to get combo pieces out of hand needs us to have a creature in play and then have a lot of one or to damage spells, Malcolm is just too unreliable in this matchup.
1x Striped Riverwinder – They have almost no way to kill an indestructible threat and killing an x/4 will take multiple removal spells in the same turn, cutting a Riverwinder feels safe.

For Izzet:

In:
1x Ashiok Dream Render - They care about their graveyard, as without it Torrential Gearhulk is just a 6/6.

Out:
1x Bitter Triumph - Their only creatures are essentially instants that happen to come attached to a body. Removal for them is much less valuable.