Altar of Dementia + Felidar Guardian + Angel of Indemnity

Altar of Dementia

Felidar Guardian

Angel of Indemnity

How it works

1. Cast Felidar Guardian by paying 3.
2. When Felidar Guardian enters the battlefield, it triggers, targeting Angel of Indemnity.
3. Holding priority, activate Altar of Dementia by sacrificing Felidar Guardian.
4. Resolve the Felidar Guardian ability, blinking Angel of Indemnity.
5. When Angel of Indemnity enters the battlefield, it triggers, returning Felidar Guardian from your graveyard to the battlefield.
6. Repeat from step 2 any number of times.
7. Resolve all abilities from step 3, milling any number of players any number of cards.