Stalwart Successor, and Ashnod's Altar

Prerequisites

• Stalwart Successor on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing the creature with persist
2. When that creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When that creature enters, Stalwart Successor triggers, putting a +1/+1 counter on it
4. Remove a +1/+1 and a -1/-1 counter from that creature as a state-based action
5. Repeat

Results

• Infinite colorless mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers