Hand of Vecna

The Hand of Vecna is an evil artifact.

Description
The hand pulses with green energy after it has been reattached.

Properties
The properties of the Hand of Vecna in the Dungeon Master's Guide, 5th Ed., which may not be canon for Critical Role, are as follows: Wondrous item, artifact (requires attunement) [...] Your alignment changes to neutral evil, and you gain the following benefits:
 * Your Strength score becomes 20, unless it is already 20 or higher.
 * Any melee spell attack you make with the Hand, and any melee weapon attack made with a weapon held by it, deals an extra 2d8 cold damage on a hit.
 * The Hand has 8 charges. You can use an action to expend 1 or more charges to cast one of the following spells (spell save DC 18) from it: finger of death (5 charges), sleep (1 charge), slow (2 charges), or teleport (3 charges). The Hand regains 1d4+4 expended charges daily at dawn. Each time you cast a spell from the Hand, it casts the suggestion spell on you (spell save DC 18), demanding that you commit an evil act. The Hand might have a specific act in mind or leave it up to you.

Background
This left hand was one of two parts of the lich lord Vecna that remained after his lieutenant, Kas the Bloody-Handed, betrayed him. The other was the left eye (the Eye of Vecna).

Vecna did not have his Hand immediately after he was reborn.

By the time Vox Machina and their allies battled Vecna over Vasselheim, three days later, his Hand was restored. In that battle, Vecna seemingly used his left hand to cast: Later in the battle, as Vecna used up his high-level spell slots, he explicitly used the Hand to cast:
 * Feeblemind
 * Meteor Swarm
 * Finger of Death
 * Teleport

Grog attempted to remove the Hand from Vecna (with the Sword of Kas, appropriately) during the fight. Arkhan grappled the Hand. Percy had considered shooting it off, but it couldn't be done.

When the party defeated Vecna and banished him, the Hand once again remained. Arkhan pretended to prepare to destroy the Hand, cut off his own left hand, somehow attuned to the artifact in an instant, and used it to Teleport away.