Triskelion + Scythe of the Wretched + Conclave Mentor

Triskelion

Scythe of the Wretched

Conclave Mentor

How it works

1. If Triskelion has more than 3 +1/+1 counters on it, activate Trislekion by removing all additional counters to deal damage to your choice of targets.
2. Activate Triskelion's ability by removing a +1/+1 counter from it to deal 1 damage to itself.
3. Repeat step 1 an additional 2 times, killing Triskelion.
4. Scythe of the Wretched triggers, returning Triskelion to the battlefield with Scythe of the Wretched attached to it.
5. Repeat.