Tom, Bert, and William, March of the Machines, and Yahenni, Undying Partisan

Prerequisites

• Tom, Bert, and William on the battlefield
• March of the Machines on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Tom, Bert, and William
2. When Tom, Bert, and William die, they trigger, returning them from your graveyard to the battlefield as a noncreature artifact
3. Because Tom, Bert, and William enter as a noncreature artifact, March of the Machines will then cause Tom, Bert, and William to be a 5/5 artifact creature
4. Resolve the Yahenni ability
5. Repeat

Results

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