Boonweaver Giant + Umbral Collar Zealot + Unhallowed Pact

Boonweaver Giant

Umbral Collar Zealot

Unhallowed Pact

How it works

1. Activate Umbral Collar Zealot 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 Umbral Collar Zealot ability from step 1.
5. Repeat.