Phyrexian Altar, and Thran Vigil

Prerequisites

• Phyrexian Altar on the battlefield
• Thran Vigil on the battlefield

Steps

1. Activate Phyrexian 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. Thran Vigil triggers, putting a +1/+1 counter on that creature
4. Remove a +1/+1 counter and a -1/-1 counter from that creature as a state-based action
5. Repeat

Results

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