Grixis Fuse Combo (Modern)

This deck is a variant on the traditional Grixis Goryo's Vengeance deck (https://www.mtggoldfish.com/archetype/modern-goryo-s-vengeance-30582#paper). It revolves around three overlapping combos--Goryo's Vengeance + a discarded fatty, Kari Zev's Expertise / Yahenni's Expertise + Breaking // Entering, Breaking // Entering + Goryo's Vengeance--which gives us a fair amount of resiliency and flexibility. Unlike the traditional Goryo's Vengeance deck, this version is more reliant on the graveyard since it doesn't run Through the Breach. But it makes up for this weakness with increased speed and power: Breaking // Entering can be cast much more quickly than Through the Breach thanks to the expertise cards and allows us to keep the creature we reanimate permanently. Breaking // Entering also allows us to dodge most non-static graveyard hate, like Surgical Extraction, Scavenging Ooze, Relic of Progenitus, etc., since fused Breaking // Entering resolves as one card without a round of priority in between each half. This means we only need to worry about Rest in Peace, Leyline of the Void, and Grafdigger's Cage.

Some notes on card choices:

Because the deck isn't running any small creatures of it's own, it uses Forbidden Orchard to insure that there is a on board creature for Kari Zev's Expertise. The tokens that Orchard produces can become annoying, especially if we have to tap Orchard for mana before the combo turn, but Yahenni's Expertise cleans them up.

The Breaking side of Breaking // Entering can be used to set up Goryo's Vengeance, although it's best to wait until you have the mana to cast both Breaking and Goryo's in case you hit an Emrakul.

Pact of Negation is a hedge against control decks, but I could see swapping them out for something in the sideboard depending on your meta. Thoughtseize might actually be a better choice because it can be used to bin our own fatties.

At the moment, I'm running Jin-Gitaxias, Core Augur as the ninth creature since it acts like a fifth Griselbrand, but I'm considering other options such as Goblin Dark-Dwellers and Narset, Enlightened Master. I originally ran Ulamog, the Infinite Gyre but found that he was a weak Goryo's Vengeance target. Annihilating four permanents and maybe dealing 10 damage was not enough to justify the resources expended on Goryo's Vengeance. As it stands, Griselbrand is usually a better Goryo's Vengeance target than Emrakul anyway because it draws you 7-14 cards and allows you to either combo again the next turn or set a up a second Goryo's Vengeance or Breaking // Entering on the spot. Emrakul is at its best as a Goryo's Vengeance target when your opponent is at 15 or less life or you can annihilate most of their board, giving your self plenty of time to reassemble the combo.

The sideboard is fairly tentative right now until I figure out exactly what the deck's weaknesses are.

Leyline of Sanctity protects us from discard.

Ancestral Vision is for grindy match ups where it can be suspended turn one or cast off of an expertise.

Wear // Tear allows us to economize on sideboard space because it can hit both Grafdigger's Cage and Rest in Peace / Leyline of the Void. It can also be cast off the expertise cards if necessary.

Swan Song can counter Rest in Peace and provides additional countermagic against control decks.

Fatal Push kills problematic creatures like Scavenging Ooze and Anafenza, the Foremost. I'm not sure if it's necessary though.

Gemstone Caverns lets us make up for lost tempo on the draw, but I'm not sure if it's worth a sideboard slot.

Other sideboard options I'm considering are Inquisition of Kozilek, Thoughtseize, Echoing Truth, Defense Grid, Silence and, more speculatively Toil // Trouble and Turn // Burn.

So far the deck has preformed very well in testing. It can go off by turn 3 regularly and has the potential for a turn one combo (Forbidden Orchard, Kari Zev's Expertise, 2 SSG, Breaking // Entering). I welcome your feedback and suggestions for improvement.