Requires

Steps

1. Activate Altar of Dementia by sacrificing Felidar Guardian.
2. When Felidar Guardian dies, its undying ability and Body Launderer's first ability trigger.
3. Resolve the Body Launderer trigger, causing it to connive.
4. Resolve the Felidar Guardian trigger, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
5. When Felidar Guardian enters the battlefield, it triggers, targeting Body Launderer.
6. Holding priority, activate Altar of Dementia by sacrificing Felidar Guardian.
7. When Felidar Guardian dies, Body Launderer's first ability triggers, causing it to connive.
8. Resolve the Altar of Dementia ability from step 6, causing target player to mill cards equal to Felidar Guardian's power.
9. Resolve the Felidar Guardian trigger from step 5, blinking Body Launderer.
10. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Felidar Guardian's power.
11. Activate Altar of Dementia by sacrificing Body Launderer.
12. When Body Launderer dies, its undying and second ability triggers.
13. Resolve the undying trigger, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
14. Resolve the second Body Launderer trigger, returning Felidar Guardian from your graveyard to the battlefield.
15. When Felidar Guardian enters the battlefield, it triggers, blinking any other permanent you control.
16. Resolve the Altar of Dementia ability from step 11, causing target player to mill cards equal to Body Launderer's power.
17. Repeat.

Results