Cowardice, Mirage Mirror, Myr Battlesphere, Krark-Clan Ironworks, and Mycosynth Golem

Prerequisites

• Cowardice on the battlefield
• Mirage Mirror on the battlefield
• Myr Battlesphere in hand
• Krark-Clan Ironworks on the battlefield
• Mycosynth Golem on the battlefield
• (at most) available

Steps

1. Cast Myr Battlesphere by paying at most
2. Myr Battlesphere enters the battlefield, creating four 1/1 Myr artifact creature tokens
3. Activate Krark-Clan Ironworks three times by sacrificing the Myr tokens, adding six
4. Activate Mirage Mirror by paying , targeting Myr Battlesphere
5. Cowardice triggers, returning Myr Battlepshere from the battlefield to your hand
6. Mirage Mirror's ability fails to resolve due to no longer having a legal target
7. Repeat

Results

• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count