The Sword of Kas

The Sword of Kas is an artifact longsword once belonging to Kas the Betrayer, loyal lieutenant and lover to Vecna before he attempted to stop her from ascending. Infused with his vampiric power and soul, the Sword is capable of untold destructive power and carries its own purpose of having Kas reunite with Vecna.

Mechanics & Inner Workings

The Sword of Kas is a +3 longsword that requires attunement. Attack and damage rolls made with it get a +3 bonus, and the wielder also gains a +3 bonus to Initiative rolls. The sword also deals an additional 1d8 or 1d10 necrotic damage on a successful hit, depending on if the wielder is one-handing or two-handing the sword.
While attuned to the sword, the wielder gains access to the following special abilities:

• When an enemy reduced to 0 HP by the sword, either by a spell or melee attack, they may arise as an undead equal to their Challenge Rating or Level (no action required), the wielder able to control them. From this ability, you can have a maximum number of active undead equal to your character level. If you create a new one using this ability, the oldest one you created is destroyed.

The sword has 9 charges and can cast the following spells by expending the listed number of charges to cast it: 

• Vampiric Slash (1 Charge): Your attack deals an additional 3d6 necrotic damage and you heal for half the damage dealt.
• Soul Chain (2 Charges): You may use your Reaction to spend 2 charges to cast the spell Soul Cage, and may automatically benefit from one of the listed exploitations of the soul. The soul does not fade after 8 hours, only being removed after using it up or by absorbing another soul with this ability.
• Soul Blast (3 Charges): As an action, you spend 3 charges and target a creature you can see within 60 feet. They and all within 30 feet of them must make a DC 19 Constitution Saving Throw. On a failure, the target suffers 8d6 necrotic damage, and all those within the radius suffer 4d6 necrotic damage. On a successful save they only suffer half damage.

The sword has its own personality and ego is Lawful Evil, and seeks to reunite with Vecna by any means necessary, including its own destruction and the death of however many it takes to do so. The wielder must make a DC 20 Wisdom Saving Throw every day it is attuned to the sword, becoming controlled by the sword if it fails. The wielder may make a new save at the end of their next long rest, but the DC increases by 1 every time they fail the save.

Significance

This weapon is said to be what heralded Vecna's ascension, as Kas wielded it in her name and slew her enemies, allowing her to ascend to true power.

Item type

Weapon, Melee

Rarity

This weapon is the only one of its kind.

Weight

6 lbs

Dimensions

3.5 feet long