Tetsuo, Imperial Champion, Savage Beating, Mystic Retrieval, Relearn, and Swarm Intelligence

Prerequisites

• Tetsuo, Imperial Champion on the battlefield
• Savage Beating in hand
• Mystic Retrieval in hand or in the graveyard
• Relearn in hand or in the graveyard
• Swarm Intelligence on the battlefield
• Tetsuo has an Equipment attached to it with mana value 5 or greater
• Tetsuo does not have summoning sickness and cannot be blocked and killed by an opponent
• One of Mystic Retrieval or Relearn must be in your hand, with the other in your graveyard

Steps

1. Declare Tetsuo as an attacker
2. Tetsuo triggers, causing you to cast Savage Beating without paying its mana cost, choosing its second mode
3. Swarm Intelligence triggers, copying Savage Beating
4. Resolve both Savage Beatings, causing you to get two additional combat phases after this one
5. Move to your first combat phase
6. Declare Tetsuo as an attacker
7. Tetsuo triggers, causing you to cast Mystic Retrieval without paying its mana cost, targeting Relearn
8. Swarm Intelligence triggers, copying Mystic Retrieval, targeting Savage Beating
9. Resolve both Mystic Retrievals, causing you to return Relearn and Savage Beating from your graveyard to your hand
10. Move to your second combat phase
11. Repeat steps 1 through 4 one additional time
12. Declare Tetsuo as an attacker
13. Tetsuo triggers, causing you to cast Relearn without paying its mana cost, targeting Mystic Retrieval
14. Swarm Intelligence triggers, copying Relearn, targeting Savage Beating
15. Resolve both Relearns, causing you to return Mystic Retrieval and Savage Beating from your graveyard to your hand
16. Move to your second combat phase, and repeat from step 1

Results

• Infinite storm count
• Infinite combat phases
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinite magecraft triggers