Derevi, Empyrial Tactician, Mycosynth Lattice, City of Shadows, and Panharmonicon

Prerequisites

• Derevi, Empyrial Tactician in the command zone
• Mycosynth Lattice on the battlefield
• City of Shadows on the battlefield
• Panharmonicon on the battlefield
• There are at least three storage counters on City of Shadows

Steps

1. Activate Derevi's ability to put him onto the battlefield from the command zone
2. Target City of Shadows with both Derevi's enter the battlefield ability and the copy of that ability from Panharmonicon
3. When the copy of Derevi's trigger untaps City of Shadows, activate City of Shadows' first ability, exiling Derevi
4. Elect to put Derevi in the command zone
5. When Derevi's trigger untapping City of Shadows, activate City of Shadows' second ability to add mana
6. Repeat

Results

• Infinite colored mana
• Infinite colorless mana
• Infinite ETB
• Infinite LTB
• Infinite untap