Charnelhoard Wurm, Great Train Heist, and Sozin's Comet

Prerequisites

• Charnelhoard Wurm on the battlefield
• Great Train Heist in hand
• Sozin's Comet in hand
• available

Steps

1. Cast Sozin's Comet by paying
2. Declare Charnelhoard Wurm as an attacker, triggering its firebending ability, adding
3. Holding priority, cast Great Train Heist by paying , selecting its first mode, causing you to untap all creatures you control and get an additional combat phase after this one
4. Deal combat damage using Charnelhoard Wurm, triggering its ability, returning Great Train Heist from your graveyard to your hand
5. Repeat from step 2

Results

• Infinite storm count
• Infinite combat phases
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinite tapped Treasure tokens
• Infinite magecraft triggers
• Infinite combat damage
• Infinitely powerful creatures you control until end of turn