Memnite, Tempered Steel, Altar of Dementia, Underworld Breach, and Thassa's Oracle

Prerequisites

• Memnite on the battlefield
• Tempered Steel on the battlefield
• Altar of Dementia on the battlefield
• Underworld Breach in hand
• Thassa's Oracle in the library
• You have four or more cards in your graveyard
• available

Steps

1. Cast Underworld Breach
2. Activate Altar of Dementia by sacrificing Memnite, milling yourself for three
3. Cast Memnite by exiling three cards from your graveyard that are not Thassa's Oracle
4. Repeat steps 2 and 3 until you have no cards in library
5. Cast Thassa's Oracle
6. Resolve its enter the battlefield trigger

Results

• Infinite self-mill
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite sacrifice triggers
• Win the game