Druid's Call + Cathars' Crusade + Triskelion + Doubling Season

Druid's Call

Cathars' Crusade

Triskelion

Doubling Season

How it works

1. Activate Triskelion by removing a +1/+1 counter from it, dealing 1 damage to itself.
2. Druid's Call triggers, creating two 1/1 Squirrel creature tokens.
3. When the Squirrels enters the battlefield, Cathars' Crusade triggers twice, putting four +1/+1 counters on each creature you control.
4. Repeat.
5. Once you have infinite +1/+1 counters on Triskelion, you may remove them to deal infinite damage to any target(s).

This loop turns Triskelion into a self-contained engine of escalation, starting simply by having it ping itself for damage. That self-inflicted damage triggers Druid's Call to spawn Squirrels, an output which Doubling Season immediately magnifies into a double-sized army. Every time those doubled tokens arrive, Cathars' Crusade seizes the moment to pump your entire board—and thanks to Doubling Season's replacement effect, those incoming counters are doubled as well, leaving Triskelion even larger than before. By repeating this process, you rapidly accumulate infinite damage, infinite creature tokens, and infinitely large creatures ready to sweep the board.