Gwenna, Eyes of Gaea, Umbral Mantle, and Nyxbloom Ancient

Prerequisites

• Gwenna, Eyes of Gaea on the battlefield
• Umbral Mantle on the battlefield
• Nyxbloom Ancient on the battlefield
• Umbral Mantle attached to Gwenna
• Gwenna does not have summoning sickness

Steps

1. Activate Gwenna by tapping it, adding six mana of any color(s) that can only be spent to cast creature spells or activate abilities of creatures
2. Activate Gwenna by paying and untapping it, giving itself +2/+2 until end of turn
3. Repeat

Results

• Infinite colored mana that can only be spent to activate abilities of creatures
• Infinite colored mana that can only be spent to cast creature spells
• Infinitely large Gwenna until end of turn