Boonweaver Giant + Altar of Dementia + False Demise

Boonweaver Giant

Altar of Dementia

False Demise

How it works

1. Activate Altar of Dementia by sacrificing Boonweaver Giant
2. When Boonweaver Giant dies, False Demise triggers, returning Boonweaver Giant from your graveyard to the battlefield
3. When Boonweaver Giant enters, it triggers, returning False Demise from your graveyard to the battlefield attached to Boonweaver Giant.
4. Resolve the Altar of Dementia ability from step 1.
5. Repeat.