Boonweaver Giant + Goblin Bombardment + Unhallowed Pact

Boonweaver Giant

Goblin Bombardment

Unhallowed Pact

How it works

1. Activate Goblin Bombardment by sacrificing Boonweaver Giant
2. When Boonweaver Giant dies, Unhallowed Pact triggers, returning Boonweaver Giant from your graveyard to the battlefield
3. When Boonweaver Giant enters, it triggers, returning Unhallowed Pact from your graveyard to the battlefield attached to Boonweaver Giant.
4. Resolve the Goblin Bombardment ability from step 1.
5. Repeat.