Mikaeus, the Unhallowed, Pith Driller, and Phantom Train

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Pith Driller on the battlefield
• Phantom Train on the battlefield

Steps

1. Activate Phantom Train by sacrifiicing Pith Driller
2. When Pith Driller dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
3. When Pith Driller enters the battlefield, it triggers, putting a -1/-1 counter on it
4. Resolve the Phantom Train ability Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite +1/+1 counters on a creature