Kirol, Attentive First-Year, Midnight Guard, and Thassa, Deep-Dwelling

Prerequisites

• Kirol, Attentive First-Year on the battlefield
• Midnight Guard on the battlefield
• Thassa, Deep-Dwelling on the battlefield

Steps

1. At the beginning of your end step, Thassa triggers
2. Holding priority, activate Kirol by tapping it and Midnight Guard
3. copying Thassa's trigger, targeting Kirol
4. Resolve the copy of Thassa's trigger, blinking Kirol
5. When Kirol enters, Midnight Guard triggers, untapping Midnight Guard
6. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control