Tarrian's Soulcleaver + Scurry Oak + Ashnod's Altar

Tarrian's Soulcleaver

Scurry Oak

Ashnod's Altar

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 Ashnod's Altar by sacrificing the Squirrel, adding CC.
4. When the Squirrel dies, Tarrian's Soulcleaver triggers, putting a +1/+1 counter on Scurry Oak.
5. Repeat from step 2.

This clever loop turns a simple squirrel nest into an engine of endless power by letting Ashnod's Altar fuel the cycle. Whenever Scurry Oak receives a counter, its triggered ability spits out a token, which you immediately sacrifice to the Altar for two colorless mana. That sacrifice sends the token straight to the graveyard, which is where Tarrian's Soulcleaver steps in: its passive ability triggers on the creature's death, placing a fresh +1/+1 counter back onto Scurry Oak to restart the entire sequence.