Grim Monolith + The Blackstaff of Waterdeep + Training Grounds

Prerequisites

• Grim Monolith does not have summoning sickness.

Steps

1. 1Activate Grim Monolith's first ability by tapping it, adding .
2. 2Activate The Blackstaff of Waterdeep by paying and tapping it, causing Grim Monolith to become an artifact creature until end of turn.
3. 3Activate Grim Monolith's second ability by paying , untapping it.
4. 4Activate Grim Monolith's first ability by tapping it, adding .
5. 5Repeat from step 3.

Effects

• Infinite colorless mana