Elite Arcanist + Great Train Heist

UR identity

Commander legal

The 2 combo pieces

• Elite Arcanist
• Great Train Heist

What must be in place

Creatures you control can tap to produce at least {3}{R}.

How to execute it

1. Activate any number of creatures by tapping it, adding at least {3}{R}.
2. Activate Elite Arcanist by paying {1} and tapping it, copying Great Train Heist and casting the copy without paying its mana cost, and choosing to pay {2}{R} to select its first mode.
3. Resolve the copy of Great Train Heist, untapping all creatures you control and get an additional combat phase if it is currently a combat phase.
4. Repeat.

What the combo produces

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