Horseshoe Crab + Omen Hawker + Rex, Cyber-Hound

WU identity

Commander legal

The 3 combo pieces

• Horseshoe Crab
• Omen Hawker
• Rex, Cyber-Hound

How to execute it

1. Activate Rex using Omen Hawker's ability by tapping it, adding {C}{U} that can only be spent to activate abilities.
2. Activate Rex using Horseshoe Crab's ability by paying {U}, untapping it.
3. Repeat.

What the combo produces

• Infinite colorless mana that can only be spent to activate abilities