Teysa, Orzhov Scion, Darkest Hour, and Yahenni, Undying Partisan

Prerequisites

• Teysa, Orzhov Scion on the battlefield
• Darkest Hour on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing another creature
2. When the creature dies, Teysa triggers, creating a 1/1 Spirit creature token that is black due to Darkest Hour
3. Resolve the Yahenni ability
4. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers