Triskelion + Scythe of the Wretched + Disciple of the Vault

Triskelion

Scythe of the Wretched

Disciple of the Vault

How it works

1. Activate Triskelion's ability by removing a +1/+1 counter from it to deal 1 damage to itself.
2. Repeat step 1 an additional 2 times, killing Triskelion.
3. Scythe of the Wretched triggers, returning Triskelion to the battlefield with Scythe of the Wretched attached to it.
4. Disciple of the Vault triggers, losing target opponent 1 life.
5. Repeat.