Idris, Soul of the TARDIS, Grim Monolith, and Illusionist's Bracers

Prerequisites

• Idris, Soul of the TARDIS on the battlefield
• Grim Monolith in exile
• Illusionist's Bracers on the battlefield
• Idris does not have summoning sickness
• Illusionist's Bracers attached to Idris
• available

Steps

1. Activate Idris using Grim Monolith's first ability by tapping it, adding
2. Activate Idris using Grim Monolith's second ability by paying
3. Illusionist's Bracers triggers, copying Idris' ability
4. Resolve the copy of Idris' ability, untapping it
5. Activate Idris using Grim Monolith's first ability by tapping it, adding
6. Resolve the Idris ability from step 2, untapping it
7. Repeat

Results

• Infinite colorless mana