Tarrian's Soulcleaver + Scurry Oak + Yahenni, Undying Partisan

Tarrian's Soulcleaver

Scurry Oak

Yahenni, Undying Partisan

How it works

1. Put a +1/+1 counter on Scurry Oak.
2. Scurry Oak triggers, creating a 1/1 Squirrel creature token.
3. Activate Yahenni by sacrificing the Squirrel.
4. When the Squirrel dies, Tarrian's Soulcleaver triggers, putting a +1/+1 counter on Scurry Oak.
5. Scurry Oak triggers, creating a 1/1 Squirrel creature token.
6. Resolve the Yahenni ability.
7. Repeat from step 3.