Mikaeus, the Unhallowed, Spawning Pit, and Pith Driller

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Spawning Pit on the battlefield
• Pith Driller on the battlefield

Steps

1. Activate Spawning Pit by sacrificing 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 Spawning Pit ability Repeat

Results

• Infinite charge counters on a permanent
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers