The Enigma Jewel // Locus of Enlightenment, and Grim Monolith

Prerequisites

• The Enigma Jewel // Locus of Enlightenment on the battlefield
• Grim Monolith on the battlefield
• The Enigma Jewel on the battlefield as Locus of Enlightenment available

Steps

1. Activate Grim Monolith's first ability by tapping it, adding Activate Grim Monolith's second ability by paying Locus of Enlightenment triggers, untapping Grim Monolith Holding priority, activate Grim Monolith by tapping it, adding Resolve Grim Monolith's ability from step 2, untapping it
2. Repeat

Results

• Infinite colorless mana