Spellbinder, and Great Train Heist

Prerequisites

• Spellbinder on the battlefield
• Great Train Heist in exile

Steps

1. Deal combat damage with the creature that has Spellbinder attached, triggering Spellbinder
2. Holding priority, activate any number of creatures you control by tapping them, adding at least
3. Resolve the Spellbinder trigger, casting a copy of Great Train Heist without paying its mana cost, and choosing to pay an additional to select its first mode, causing you to untap all creatures you control and to get an additional combat phase after this one
4. Repeat each combat phase

Results

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