The Sword of Kas is a sentient, versatile black longsword once wielded by Kas the Bloody-Handed when he rebelled against Vecna. After Kas' death, the Sword of Kas went missing in the depths of Thar Amphala until it was found by Keyleth. It was then given to Grog Strongjaw.
The Sword of Kas seeks blood and the downfall of Vecna. As an NPC, the Sword of Kas is portrayed by Matthew Mercer.
The Sword of Kas is singularly focused on destroying Vecna and his followers. Besides its thirst for blood, the main thing the Sword talks about is that "the lich must die." When used to attack Vecna, the Sword discussed wanting to usurp Vecna's power for itself.
Vecna forged a relic blade for his new vampire lieutenant with a fraction of Kas's consciousness. Kas used it to terrorize Vecna's enemies for months. When Vecna first attempted to ascend to godhood with the Ritual of Seeding, Yos Varda attacked Vecna directly. Though Vecna defeated Yos, the effort left him winded, and as Yos lay dying, Kas picked that moment to attack Vecna with the blade in an attempt to usurp him. The ensuing battle destroyed both Vecna and Kas, but the sword remained—though it was not recovered.
"Dark Dealings" (1x112)
Beaneath Thar Amphala, Vex uses a Scrying Eye on the Sword and sees it submerged in muck, but gets a good enough description of the object to allow her to cast Locate Object and discover that it was within 1,000 feet. They make their way directly above the object. Keyleth, in earth elemental form, earthglides down to a small chamber 150 feet below—a room cut off by a collapse—with a pool of acid that has been used for disposing of bodies and other unwanted things. Her elemental form incurs acid damage and avoids being grappled by undead skeletal hands to recover the Sword, and Vex (who had used Oil of Etherealness to drop down to the chamber, unaware that it make her useless for a full hour) returns to the party with the Sword via a Gate Stone.
However, the plan to retrieve the Sword has some holes, and it reveals Vox Machina's location to Vecna. Under attack by the Briarwoods, they are forced to retreat to the Feywild. Grog immediately begins attuning to the Sword, and the party is introduced to the Sword's motivations and its thirst for blood.
"The Final Ascent" (1x113)
"Vecna, the Ascended" (1x114)
"The Chapter Closes" (1x115)
- Scores a critical hit on a 19 or 20.
- Deals an extra 2d10 slashing damage to undead.
- If the Sword of Kas isn't bathed in blood within a minute of being drawn from its scabbard, its wielder must make a DC 15 Charisma save. On a success, they suffer 3d6 psychic damage. On a failure, they are dominated by the sword (as if by dominate monster) and the sword demands that it be fed blood. The effect ends when the sword is fed.
- Absorbs blood.
- Random Properties
- Minor Beneficial Property: Wielder gains proficiency in one skill while attuned.
- Major Beneficial Property: Wielder's Constitution score increases by 2 while attuned, to a maximum of 24.
- Minor Detrimental Property: Wielder becomes gaunt, their skin turns pale, and their eyes turn a faint red.
- Major Detrimental Property: On attuning, wielder takes (8d10?) psychic damage.
- Spirit of Kas
- While the sword is on wielder, they add a d10 to initiative at the start of every combat.
- The wielder can transfer some or all of the sword's attack bonus to their AC when they use an action to attack. This lasts until the beginning of their next turn.
- Spells: While the sword is on wielder, they can use an action to cast call lightning, finger of death, or divine word from it (save DC 18) once per day. Each spell recharges at dawn.
- Critical Role: Tal'Dorei Campaign Setting, p. 38.
- See "The Endless Atheneum" (1x106) at 1:19:58.
- See "Dark Dealings" (1x112) from 1:56:56 through 2:02:51.
- See "Dark Dealings" (1x112) from 2:31:13 through 3:00:54.
- See "Dark Dealings" (1x112) from 3:07:20 through 3:23:26.
- See "Dark Dealings" (1x112) at 3:17:25.
- See "The Final Ascent" (1x113) at 1:55:34.
- See "The Final Ascent" (1x113) at 2:32:13. Travis and Matt discuss the extra 2d10 not applying to Delilah because she is alive
- See "Dark Dealings" (1x112) from 3:11:37 through 3:16:38. Grog is dominated by the Sword of Kas
- See "Dark Dealings" (1x112) at 3:21:03.
- See "Talks Machina #40: 'Dark Dealings'" (TMx40).
- See "Talks Machina #40: 'Dark Dealings'" (TMx40).
- See "Dark Dealings" (1x112) at 3:13:05.
- See "Dark Dealings" (1x112) at 3:12:56. Grog took 38 points of psychic damage by attuning to the sword. Of the random Major Detrimental Properties in the DMG, two deal psychic damage: one deals 4d10 psychic damage on attunement, and one deals 8d10 psychic damage on attunement. Rolling 4d10 has a 0.1% chance of resulting in 38, whereas rolling 8d10 has a 3.74% chance of resulting in 38; it is more likely that attuning to the sword deals 8d10 psychic damage, but it's impossible to be sure without an official item description
- See "The Final Ascent" (1x113) at 58:11. Travis notes that he adds a d10 to his initiative roll
- See "Vecna, the Ascended" (1x114) at 2:54:22. Travis contemplates casting Finger of Death through the Sword of Kas