Lita, Mechanical Engineer, Strionic Resonator, and Karn, the Great Creator

Prerequisites

• Lita, Mechanical Engineer on the battlefield
• Strionic Resonator on the battlefield
• Karn, the Great Creator on the battlefield
• You control artifact creatures that can tap to add at least
• Strionic Resonator does not have summoning sickness

Steps

1. Activate Karn by putting a loyalty counter on them, causing Strionic Resonator to become an artifact creature until end of turn
2. At the beginning of your end step, Lita triggers
3. In response, activate artifact creatures by tapping them to add at least
4. Continuing to hold priority, activate Strionic Resonator by paying and tapping it, copying Lita's triggered ability
5. Resolve the copied ability, untapping all artifact creatures you control
6. Repeat from step 3

Results

• Infinite mana artifact creatures you control can produce
• Infinite untap of artifact creatures you control