Breath of Fury, and Siege-Gang Lieutenant

Prerequisites

• Breath of Fury on the battlefield
• Siege-Gang Lieutenant on the battlefield
• Breath of Fury attached to any creature that can attack this turn
• An opponent is unable to block and kill creatures you control
• You control your commander

Steps

1. At the beginning of combat phase, Siege-Gang Lieutenant triggers, creating two 1/1 Goblin creature tokens and giving them haste until end of turn
2. Deal combat damage using the creature with Breath of Fury attached
3. Breath of Fury triggers, causing you to sacrifice the creature it is attached to, attach Breath of Fury to a Goblin token, then untap all creatures you control and get an additional combat phase after this one
4. Repeat each combat phase

Results

• Infinite combat damage
• Infinite combat phases
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of creatures you control