General Kreat, the Boltbringer, Breath of Fury, and Garna, the Bloodflame

Prerequisites

• General Kreat, the Boltbringer on the battlefield
• Breath of Fury on the battlefield
• Garna, the Bloodflame on the battlefield
• You control at least one Goblin
• An opponent cannot block creatures you control

Steps

1. Declare the creature with Breath of Fury attached, and at least one Goblin if the creature with Breath of Fury attached isn't an Assassin, as attackers
2. General Kreat's first ability triggers, creating a 1/1 Goblin creature token that's tapped and attacking
3. When the Goblin enters the battlefield, General Kreat's second ability triggers, dealing 1 damage to each opponent
4. Deal combat damage using the creature that has Breath of Fury attached
5. Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to the Goblin token, then causing you to untap all creatures you control and to get an additional combat phase after this one
6. Repeat each combat phase

Results

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