Elite Arcanist, and Great Train Heist

Prerequisites

• Elite Arcanist on the battlefield
• Great Train Heist in exile

Steps

1. Activate any number of creatures by tapping it, adding at least
2. Activate Elite Arcanist by paying and tapping it, copying Great Train Heist and casting the copy without paying its mana cost, and choosing to pay 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

Results

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