Felidar Guardian + Vesperlark + Altar of Dementia

Felidar Guardian

Vesperlark

Altar of Dementia

How it works

1. Cast Felidar Guardian by paying 3.
2. When Felidar Guardian enters the battlefield, it triggers, targeting Vesperlark.
3. Holding priority, activate Altar of Dementia by sacrificing Felidar Guardian.
4. Resolve the Felidar Guardian trigger, blinking Vesperlark.
5. When Vesperlark leaves the battlefield, it triggers, returning Felidar Guardian from your graveyard to the battlefield.
6. Repeat from step 2.