Hellkite Charger, and Sozin's Comet

Prerequisites

• Hellkite Charger on the battlefield
• Sozin's Comet in hand or in exile
• at most available

Steps

1. Cast Sozin's Comet either from your hand by paying or from exile for its foretell cost by paying , causing each creature you control to gain firebending 5 until end of turn
2. Declare Hellkite Charger and at least one other creature as attackers, triggering each creature's firebending ability and Hellkite Charger
3. Resolve each firebending trigger, adding for each attacking creature
4. Resolve the Hellkite Charger trigger, causing you to pay to untap all attacking creatures and to get an additional combat phase after this one
5. Repeat from step 2 each combat phase

Results

• Infinite combat phases
• Infinite red mana
• Infinite combat damage