Mad Monk

The Mad Monk was a prisoner of the planeswalker Geyadrone Dihada on Dominaria.

He helped Carth escape the prison and find the Amulet of Ti-Fu and the grimoire to summon Dakkon Blackblade, and so defeat Geyadrone Dihada.

In the end, it was revealed that the monk was in reality a disguised Geyadrone, who in this way put in motion her plot to eventually use the might of Dakkon to kill an Elder Dragon, absorbing its power and subduing the warrior.