Prowling Geistcatcher, Pawn of Ulamog, Shambling Ghast, Cadaver Imp, and Altar of Dementia

Prerequisites

• Prowling Geistcatcher on the battlefield
• Pawn of Ulamog on the battlefield
• Shambling Ghast on the battlefield
• Cadaver Imp on the battlefield
• Altar of Dementia on the battlefield
• You control at least one additional nontoken creature

Steps

1. Activate Altar of Dementia four times by sacrificing Cadaver Imp, Shambling Ghast, Pawn of Ulamog and another nontoken creature
2. Pawn of Ulamog and Prowling Geistsnatcher trigger four times each, and Shambling Ghast triggers once
3. Resolve the Shambling Ghast trigger, creating a Treasure token
4. Resolve all Pawn of Ulamog triggers, creating four 0/1 Eldrazi Spawn creature tokens
5. Resolve all Prowling Geistsnatcher triggers, exiling the sacrificed creatures
6. Resolve all Altar of Dementia abilities, causing target player to mill cards equal to the sacrificed creatures' powers
7. Activate Altar of Dementia by sacrificing Prowling Geistsnatcher
8. Prowling Geistsnatcher leaves the battlefield, returning all cards exiled with it to the battlefield
9. Cadaver Imp enters the battlefield, returning Prowling Geistsnatcher from your graveyard to your hand
10. Resolve the Altar of Dementia ability from step 7, causing target player to mill cards equal to Prowling Geistsnatcher's power
11. Activate three Eldrazi Spawn tokens by sacrificing them, adding
12. Activate the Treasure by tapping and sacrificing it, adding
13. Cast Prowling Geistsnatcher by paying
14. Repeat

Results

• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill
• Infinite storm count