Marvin, Murderous Mimic, Farmstead Gleaner, and Vhal, Candlekeep Researcher

Prerequisites

• Marvin, Murderous Mimic on the battlefield
• Farmstead Gleaner on the battlefield
• Vhal, Candlekeep Researcher on the battlefield

Steps

1. Activate Marvin using Vhal's ability by tapping it, adding an amount of equal to Marvin's toughness that cannot be spent to cast spells from your hand
2. Activate Marvin using Farmstead Gleaner's ability by paying and untapping it, putting a +1/+1 counter on Marvin
3. Repeat

Results

• Infinite colorless mana that can't be spent to cast spells from your hand
• Infinite +1/+1 counters on a creature