Kirol, Attentive First-Year, Sunstrike Legionnaire, and The Mind Stone

Prerequisites

• Kirol, Attentive First-Year on the battlefield
• Sunstrike Legionnaire on the battlefield
• The Mind Stone on the battlefield

Steps

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

Results

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