Weapon (greataxe), legendary (requires attunement)

The blade of this massive axe is crafted from raw destructive energy. It appears jet black in daylight and shimmers slightly in moonlight. Gorm can wield this axe in one hand. It has a +3 bonus to attack and damage rolls and deals 3d10 slashing damage when wielded by Gorm.

If a creature damaged by the axe would be resistant or immune to the damage dealt by the axe, it is instead not resistant or immune.

Creatures at 0 hit points that are hit by this axe are slain instantly, their souls utterly destroyed. They cannot be returned to life by any known means. The bodies of the creatures slain are reduced to dust, along with all their possessions. Magical items of uncommon rarity or lower are destroyed, while rare or better magical items survive, remaining intact among the pile of dust.

If Gorm’s body is destroyed while wielding this axe, the axe does not disappear like the rest of its equipment. The axe falls to the ground, digging into whatever surface is there and waiting, handle up, for someone to take it. The axe remains there for one minute before vanishing, unless someone else claims it first. If a creature draws the axe from the ground, Gorm immediately manifests, forging a new body out of pure hate within 500 ft. of Interitus’s new wielder, and a new battle begins.

In the hands of creatures other than Gorm, Interitus is merely a greataxe that grants a +3 bonus to attack and damage rolls, but if Gorm is slain by this axe, its soul is permanently destroyed, never to return.

Ref: T&H p108