Spawning Pit, and Good-Fortune Unicorn

Prerequisites

• Spawning Pit on the battlefield
• Good-Fortune Unicorn on the battlefield

Steps

1. Activate Spawning Pit by sacrificing the persist creature
2. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When the persist creature enters, Good-Fortune Unicorn triggers, putting a +1/+1 counter on that creature Resolve the Spawning Pit ability
4. Repeat

Results

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