The Monks of the Undying Hand guard the the Sinistra Arcanum, a Library of Vecna hidden deep in the dark forests of the Shadowfell. They are the keeper of its secrets, and have pledged their lives and their deaths to the Undying God. Those that leave the walls of the Library serve as spies and assassins for the Order. Within the walls of the Monastery, they dress in simple, black robes. But, when outside the walls of the Library, they keep their true allegiances hidden. Those higher in the Order have have their left eyes ritually removed and replaced with a dark gem engraved in arcane runes in a secret language. Their left hands may appear skeletal and blackened, but are charged with necrotic energy, which they use in combat with deadly efficiency. They have been known to wander the Prime Material Plane in search of both secrets and sacrifices for their dark god.

Dark Shadow

Starting at 3rd level, you can use a bonus action to place Dark Shadow on a creature that you can see within 30 feet of you. The shadow lasts for 10 minutes, or until you fall unconscious, or the creature dies. Until Dark Shadow ends, you gain advantage on the first attack roll you make against that creature each turn, and you know the distance and in what direction that creature is from you. You may have only one creature marked in this way, with any new Dark Shadow replacing and ending an already existing one. You may use this feature a number of times equal to your Wisdom modifier, regaining all uses when you complete a long rest.

Channel Death

Starting at 6th level, once per turn with a Monk weapon or unarmed attack, you can spend up to a number of Ki Points equal to your Wisdom modifier to deal additional necrotic damage. This damage is equal to 1 Martial Arts die per Ki Point spent this way + your Wisdom modifier.

Last Breath

Beginning at 11th level, you use your knowledge of death to escape its grasp. When you are reduced to 0 hit points, you can expend 1 ki point (no action required) to have 1 hit point instead.

The Touch of Vecna

Starting at 17th level, your touch can channel the power of the Undying God. As an action, you touch one creature within 5 feet of you, and you expend 1 to 10 ki points. The target must make a Constitution saving throw, and it takes 3d6 necrotic damage per ki point spent on a failed save, or half as much damage on a successful one.