Myr Welder, Umbral Mantle, and Timeless Lotus

Prerequisites

• Myr Welder on the battlefield
• Umbral Mantle on the battlefield
• Timeless Lotus in exile

Steps

1. Activate Myr Welder using Timeless Lotus's ability by tapping it, adding
2. Activate Myr Welder by paying and untapping it, giving it +2/+2 until end of turn
3. Repeat

Results

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