Mikaeus, the Unhallowed + Ashcloud Phoenix + Goblin Bombardment

Mikaeus, the Unhallowed

Ashcloud Phoenix

Goblin Bombardment

How it works

1. Activate Goblin Bombardment by sacrificing Ashcloud Phoenix.
2. When Ashcloud Phoenix dies, it triggers, as well as its undying ability if it does not have a +1/+1 counter on it.
3. Resolve the first trigger, returning it from your graveyard to the battlefield face-down.
4. Resolve the second trigger, doing nothing.
5. Activate Goblin Bombardment by sacrificing Ashcloud Phoenix.
6. When Ashcloud Phoenix dies, it triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
7. Resolve the Goblin Bombardment abilities from steps 1 and 5, dealing 2 damage to any target.
8. Repeat.