Training Grounds, Umbral Mantle, and Arixmethes, Slumbering Isle

Prerequisites

• Training Grounds on the battlefield
• Umbral Mantle on the battlefield
• Arixmethes, Slumbering Isle on the battlefield
• Arixmethes is a creaure and does not have summoning sickness
• Umbral Mantle attached to Arixmethes

Steps

1. Activate Arixmethes by tapping it, adding
2. Activate Arixmethes by paying and untapping it, giving it +2/+2 until end of turn
3. Repeat

Results

• Infinite colored mana
• Infinitely large Arixmethes until end of turn