Biomancer's Familiar + Gyre Engineer + Umbral Mantle

GU identity

Commander legal

The 3 combo pieces

• Biomancer's Familiar
• Gyre Engineer
• Umbral Mantle

What must be in place

Umbral Mantle attached to Gyre Engineer.
Gyre Engineer does not have summoning sickness.

How to execute it

1. Activate Gyre Engineer by tapping it, adding {G}{U}.
2. Activate Gyre Engineer by paying {1} and untapping it, giving itself +2/+2 until end of turn.
3. Repeat.

What the combo produces

• Infinite blue mana
• Infinite green mana
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control
• Infinitely large creature until end of turn