Enduring Renewal + Composer of Spring + Altar of Dementia

Enduring Renewal

Composer of Spring

Altar of Dementia

How it works

1. Cast the enchantment creature by paying its mana cost.
2. When the creature enters the battlefield, Composer of Spring triggers.
3. Holding priority, activate Altar of Dementia by sacrificing the enchantment creature.
4. When the enchantment creature dies, Enduring Renewal triggers, returning the enchantment creature to your hand from your graveyard.
5. Resolve the Altar of Dementia ability from step 3, causing target player to mill cards equal to the sacrificed creature's power.
6. Resolve the Composer of Spring trigger from step 2, putting the enchantment creature onto the battlefield from your hand.
7. Repeat from step 2.