Breed Lethality Upgrade (EDH / Commander)

The maybeboard lists cards that I've considered adding to the deck but for whatever reason haven't done it yet (i.e. not knowing what to cut for them, or simply not being sure if I actually want to add them or not).
The sideboard lists cards that I've recently cut, cards that can still be optionally swapped back in will remain there while cards that shouldn't be swapped back in will probably be removed later.

The deck is themed around +1/+1 counters, as I found this to be the most enjoyable archetype for Atraxa, Praetors' Voice. I am trying to avoid spending a fortune on upgrading Breed Lethality as I am also working on a Muldrotha deck that's turning out to be particularly expensive, so there are almost certainly some stronger cards out there that would be a perfect fit if it were not for their hefty price tag (for example, Doubling Season). I've also put more of an emphasis on actually having fun with the deck rather than trying to end the game the moment it gets to turn 3 or something dumb, so while I wouldn't call the deck bad it's certainly not a competitive EDH deck.

Reyhan, Last of the Abzan and Ishai Ojutai Dragonspeaker can be used as the alternate commander(s) in place of Atraxa, Praetors' Voice (in this scenario, you'd just include Atraxa as one of the creatures in the deck). While this is a very strong option, I prefer to keep Atraxa as the commander as the consistent proliferating she provides is incredibly valuable for the rest of the deck.

Under Card Explanations I will talk about some of the cards I've added and why I've added them, as well as some cards that were already in the precon that I feel the need to discuss (i.e. explain why they've not been cut or just to put emphasis on how cool a card is). Under To-Do I will list some changes that I feel need to be made to the deck, or some changes that I think could be kind of fun.

Card Explanations:
Creatures:
Chasm Skulker - Self sufficient big dude that gives you many little dudes on death. Chasm Skulker is a great card and if you have cards like Juniper Order Ranger or Cathars' Crusade on the board things will get nuts when Chasm Skulker dies.
Herald of Secret Streams - Originally added with the mindset of using him as a finisher card, Herald of Secret Streams has also proven to be incredibly useful for getting safe attacks in on opponents planeswalkers. All round great card in this deck.
Managorger Hydra - Essentially acts as a second copy of Ishai, Ojutai Dragonspeaker, except better in that Managorger Hydra will also grow off of you casting spells.
Odric, Lunarch Marshal - This card is kind of the odd one out. He's not synergistic with the +1/+1 counter theme whatsoever, but he's in the deck for a very good reason. Atraxa, Praetors' Voice is a card with four keywords on her, those keywords being flying, vigilance, deathtouch and lifelink. This is pretty damn good, however what if could swing with an entire board of creatures with flying, vigilance, deathtouch and lifelink? With Atraxa and Odric on the board, your already scary bombs become a whole lot scarier.
Shalai, Voice of Plenty - She protects you and your board from all targeted effects while also providing you with a means to spend excess mana to pump up your entire board with +1/+1 counters. Pretty damn good card.
Voracious Hydra - Can either be used to remove an opponents creature and give yourself a pretty big dude, or to give yourself an even bigger dude. Choosing to have Voracious Hydra double its' +1/+1 counters as it enters the battlefield is kind of nuts when you have cards like Corpsejack Menace out alongside it.
Walking Ballista - I'm not going to lie the main reason this card is in this deck is because I pulled it from a pack that came with the very first MTG product I bought and I've been itching to actually use it ever since. That being said, Walking Ballista is an incredible card in a deck themed around adding +1/+1 counters to things and proliferating. Feel free to laugh maniacally when you load the card up with an absurd amount of +1/+1 counters and proceed to machine gun your opponents creatures until there's nothing left but tiny little pieces of torn magic cards. When this card pops off it really pops off. It can also be used as a way to finish off an opponent on low health.
Zegana, Utopian Speaker - She provides a little bit of card draw while also giving your other creatures trample so long as they have +1/+1 counters on them. Simple enough. Being able to adapt her to put four +1/+1 counters on her is pretty damn good as well, and can work out to be quite the substantial buff when you use it alongside effects such as Corpsejack Menace and Hardened Scales.
Reveillark - This card came with the Breed Lethality precon and I had originally planned to remove it from the deck. However, in many of the more recent games I've played I've found that the deck actually has a sizable amount of creatures to bring back with Reveillark, with Ghave, Guru of Spores and Reyhan, Last of the Abzan being some prime examples of this.

Instants:
Arcane Denial - The lack of counterspells was really hurting this deck.
Swords to Plowshares - Cheap and easy creature removal.

Sorceries:
Cultivate - A pretty simple card that doesn't really need a lengthy explanation, having lands is better than not having lands.
Supreme Verdict - A final middle finger to the board, it's an incredibly strong board wipe that has saved my ass more times than I can count. Obviously you try to avoid using it when you've got a big board yourself but sometimes there's just no other option. I replaced Duneblast with it as, while Duneblast letting you save one creature was handy, it just had too high a mana cost to justify using over Supreme Verdict, and Supreme Verdict being immune to counterspells helps a lot.

Enchantments:
Bred for the Hunt - Not too much to say about this one, it provides some very handy card draw as long as you've got creatures with +1/+1 counters to swing with.
Inexorable Tide - At times it's not that impactful (to the point where I have considered removing it on numerous occasions) but it has proven to be pretty damn useful in some of the games I've played with it. It is one of the cards I might consider cutting for some counterspells (more on that further down the page).
Simic Ascendancy - Provides the deck with another means of getting +1/+1 counters onto creatures and an alternate win condition that is achieved by just playing the deck the way you'd play it if Simic Ascendancy wasn't present. It's a very synergistic card with this deck, and one thing to note is that proliferating helps speed it up more than usual as you can proliferate the growth counters on Simic Ascendancy as well as the +1/+1 counters on your creatures.

Artifacts:
Sword of Truth and Justice - Originally I had added Grafted Exoskeleton to the deck (along with Phyrexian Swarmlord), however Grafted Exoskeleton was performing pretty poorly in the deck so I removed it and any other infect cards. In its' place I've added Sword of Truth and Justice as the sword provides a means to actually put +1/+1 counters onto your creatures, something incredibly useful as I have often played games where I get a lot of my creatures or proliferate engines out but have no means of actually putting +1/+1 counters on them to proliferate, while also providing another proliferate engine (and makes Atraxa even nastier if you equip it on her). The protection from white and blue is just icing on the cake.
Talisman of Curiosity - I have replaced Simic Signet with Talisman of Curiosity as I prefer the talismans and personally feel that the talismans are better than signets.
Talisman of Hierarchy - See above.
Talisman of Resilience - See above.

Planeswalkers:
Tamiyo, Field Researcher - Tamiyo provides some nice card draw and can slow down opponents by tapping their stuff, however the real attraction here is her ult. Tamiyos ult provides the deck with an omniscience that's a little harder to get on the field (although with proliferating you can accelerate the rate at which you get Tamiyo to ult) but once it's out there's no way for any opponent to get rid of it.

Lands:
Reliquary Tower - Despite being in black, the deck barely runs any recursion. As a result having to discard some of your bombs is a fate you'd want to avoid, hence Reliquary Tower.
The Vivid Lands (Vivid Creek, Vivid Grove, Vivid Marsh, Vivid Meadow) - These were added on the suggestion of a friend and that has turned out to be one of the greatest suggestions that friend has ever given me. The vivid lands are pretty solid on their own, providing some clutch mana fixing, however with Atraxa, Praetors' Voice providing you a means of replenishing their charge counters you will find yourself almost always being able to tap a vivid for whatever kind of mana you want.
Triomes - fetchable tri-colour lands (not that the first part is relevant unless running fetch lands), being able to cycle these when mana flooded is very nice.
Shock Lands - 'nuff said.
Karn's Bastion - An extra proliferate engine that is hard to remove due to being a land.
Gavony Township - Hard to remove +1/+1 counter generation.
Bojuka Bog - Graveyard hate.

Further Upgrades:

• Fetch lands - need to have "the talk" with your playgroup before going ahead with these (also need to have the "other talk" with your bank account).
• Bond lands - good for multiplayer, bad for 1v1, I opted for the shocks over these but use whichever is more readibly available to you. In an idea world I'd probably consider using some of both.
• Recursion/reanimation - got some bombs in this deck, being able to recur them is something I need to play with.
• Contagion Engine - powerful proliferate engine that lets you ult Kaya the Inexorable the turn you play her.

Alternative or Budget Options:

• Fellwar Stone can be kept in place of Arcane Signet and provide similar results if upgrading from the precon.
• Counterspell - could replace Arcane Denial but will be harder to cast and won't give you the draw, but on the flipside won't draw your opponent cards.
• Putrefy - cheaper alternative to Assassin's Trophy and comes with the precon.
• Proliferate engines or +1/+1 counter generators - pricey cards such as Vorinclex may be swapped out for any suitable alternatives so long as they still provide you with a means to put +1/+1 counters on things.