Guardian of the Forgotten, and Demonmail Hauberk

Prerequisites

• Guardian of the Forgotten on the battlefield
• Demonmail Hauberk on the battlefield

Steps

1. Activate Demonmail Hauberk's equip ability by sacrificing the creature it is attached to, targeting another creature you control
2. When the creature dies, Guardian of the Forgotten triggers, causing you to manifest the top card of your library
3. Resolve the Demonmail Hauberk trigger, attaching it to the targeted creature
4. Repeat

Results

• Infinite self-mill
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite death triggers
• Near-infinite sacrifice triggers