Doors of Durin + Breath of Fury + Mortuary

Prerequisites

• You have a creature card that has haste on top of your library.
• Breath of Fury attached to a nontoken creature you control that has haste.
• An opponent cannot block creatures you control.

Steps

1. 1Declare the creature with Breath of Fury attached as an attacker.
2. 2Doors of Durin triggers, causing you to scry 2, ensuring to leave the creature card with haste on top of your library, then revealing the creature card and putting it onto the battlefield tapped and attacking.
3. 3Deal combat damage using the creature that has Breath of Fury attached.
4. 4Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to the creature Doors of Durin returned, then causing you to untap all creatures you control and to get an additional combat phase after this one.
5. 5When the creature dies, Mortuary triggers, putting the creature on top of your library from your graveyard.
6. 6Repeat each combat phase.

Effects

• Infinite combat damage
• Infinite combat phases
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control