Druid's Call + Cathars' Crusade + Triskelion + Primal Vigor

Druid's Call

Cathars' Crusade

Triskelion

Primal Vigor

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 is a masterclass in compounding growth, fueled by the brilliant synergy between Triskelion and Druid's Call. By having Triskelion deal damage to itself, Druid's Call generates Squirrel tokens that are immediately doubled by Primal Vigor. Each of those entering tokens triggers Cathars' Crusade twice thanks to Primal Vigor's doubling effect on counters, showering your board with an exponentially growing number of +1/+1 counters. This feeds right back into Triskelion, supplying it with the endless ammunition needed to keep the cycle spinning and ultimately obliterate any target you choose.