Marvin, Murderous Mimic, Synthesizer Labship, and Lost Jitte

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Synthesizer Labship on the battlefield
• Lost Jitte on the battlefield

Steps

1. Animate the land, if needed
2. At the beginning of your combat phase, Synthesizer Labship triggers, animating Lost Jitte
3. Activate Marvin using Synthesizer Labship's station ability by tapping the animated land, putting a number of charge counters on Marvin equal to the animated land's power
4. Activate Marvin using Lost Jitte's ability by removing a charge counter from it, untapping the animated land
5. Repeat from step 3

Results

• Infinite mana lands you control can produce
• Infinite untap of lands you control