Spawning Pit, and Combine Guildmage

Prerequisites

• Spawning Pit on the battlefield
• Combine Guildmage on the battlefield
• available

Steps

1. Activate Combine Guildmage's first ability by paying and tapping it, causing your creatures that enter this turn to enter with a +1/+1 counter on them
2. Activate Spawning Pit by sacrificing the persist creature
3. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it and at least one +1/+1 counter on it due to Combine Guildmage
4. Remove a -1/-1 counter and a +1/+1 counter from that creature as a state-based action
5. Resolve the Spawning Pit ability
6. Repeat from step 2

Results

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