Body Launderer, Felidar Guardian, Mikaeus, the Unhallowed, and Altar of Dementia

Prerequisites

• Body Launderer on the battlefield
• Felidar Guardian on the battlefield
• Mikaeus, the Unhallowed on the battlefield
• Altar of Dementia on the battlefield
• Felidar Guardian does not have a +1/+1 counter on it

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

• Infinite card draw
• Infinite draw triggers
• Infinite looting
• Near-infinite blinking of permanents you control
• Near-infinite death triggers
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite mana permanents you control can produce
• Near-infinite mill
• Near-infinite sacrifice triggers
• Infinite self-mill