Tree-skaidekaphobia B/G (Standard)

Combo 1:
Triskaidekaphobia makes a player with 13 life lose the game. Tree of Perdition has the ability to exchange an opponent's life total with its toughness (which just so happens to be 13). That's what we in the biz like to call a combo. Seriously though, if it wasn't for pesky painlands giving opponents the ability to drain their own life, this would easily be the best Tree of Perdition combo in Standard, but since painlands are not only in the format but super popular, counting on winning with Tree of Perdition and Triskaidekaphobia alone is risky.

Combo 2: Tree of Perdition with Tainted Remedy. While this combo is a little bit slower than the instant-win potential of Triskaidekaphobia, it's also much harder to disrupt. While it might not be obvious at first glance, one of the things that Tree of Perdition can do is force an opponent to gain big chunks of life (technically, when we make the exchange of toughness for life total, if Tree of Perdition's toughness is greater than our opponent's life total, they are gaining life).

One of the great aspects of this combo is that it directly combats the easiest way our opponent can disrupt the Triskaidekaphobia kill (getting their own life total below 13), because if our opponent's life total is less than 13, our very first activation of Tree of Perdition with a Tainted Remedy on the battlefield will start draining our opponent's life total, and each subsequent activation will drain for an even greater amount. In many cases, it only takes three activations to get our opponent from 20 all the way down to zero.

Strider Harness might look weird, but it does two things. First, it can give our Tree of Perdition haste, which allows for some sweet surprise kills with Tainted Remedy. Second, it boosts Tree of Perdition's toughness to 14. One of the ways the Tainted Remedy plan can fail is if our opponent is at exactly 13 life, because in this scenario, activating Tree of Perdition does nothing. If this happens (for example, because we had activated a Tree of Perdition earlier in the game), we can equip the Strider Harness to allow our Tree of Perdition to start forcing our opponent to lose life with the help of Tainted Remedy, even if our opponent is at exactly 13 life.

Combo 3: involves a Tree of Perdition in the graveyard and a Soul Separator on the battlefield, which allows us to sacrifice the Soul Separator to make a 1/1 flying Tree of Perdition token (along with a 0/13 Zombie token for blocking). Then, we can simply tap the 1/1 Tree of Perdition token to set our opponent's life total to one (and give our token a ton of toughness). The last piece of the puzzle is Collective Brutality, which we can use to drain our opponent for two and win the game!

Combo 4: Assault Formation, which turns our Tree of Perdition into a 13/13 for only four mana and lets it attack, even though it has defender. Assuming we get in one Tree of Perdition activation before going on the beatdown plan, we only need to connect with one Tree of Perdition attack to win the game. We also have Permeating Mass (a 3/3 for one mana with Assault Formation on the battlefield) to help out when we go on the creature beatdown plan, while also providing a hilarious roadblock against aggressive decks.