Mikaeus, the Unhallowed, Spawning Pit, and Dream Seizer

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Spawning Pit on the battlefield
• Dream Seizer on the battlefield

Steps

1. Activate Spawning Pit by sacrificing Dream Seizer
2. When Dream Seizer dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
3. When Dream Seizer 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