Cavalier of Night + Activated Sleeper + Altar of Dementia

Cavalier of Night

Activated Sleeper

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Cavalier of Night.
2. When Cavalier of Night dies, it triggers, returning Activated Sleeper from your graveyard to the battlefield as a copy of Cavalier of Night.
3. When Activated Sleeper enters the battlefield, its first triggered ability from Cavalier of Night triggers; choose not to sacrifice a creature.
4. Resolve the Altar of Dementia ability from step 1.
5. Activate Altar of Dementia by sacrificing Activated Sleeper.
6. When Activated Sleeper dies, its last ability from Cavalier of Night triggers, returning itself from your graveyard to the battlefield as a copy of Cavalier of Night.
7. When Activated Sleeper enters the battlefield, it triggers; choose not to sacrifice a creature.
8. Resolve the Altar of Dementia ability from step 5.
9. Repeat from step 5.