Mikaeus, the Unhallowed + Defiant Greatmaw + Goblin Bombardment

Mikaeus, the Unhallowed

Defiant Greatmaw

Goblin Bombardment

How it works

1. Activate Goblin Bombardment by sacrificing Defiant Greatmaw.
2. When Defiant Greatmaw dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
3. When Defiant Greatmaw enters the battlefield, its first ability triggers, putting two -1/-1 counters on it.
4. Defiant Greatmaw's second ability triggers, removing a -1/-1 counter from another creature you control.
5. Resolve the Goblin Bombardment ability from step 1, dealing 1 damage to any target.
6. Repeat.