Umbra Greatswords (Japanese: ダーク・クレイモア, Dāku Kureimoa) are Weapon Accessories in Xenoblade Chronicles 2: Torna ~ The Golden Country. They can only be equipped by Addam and imbue his attacks with the Dark element.
All Greatsword weapon accessories increase Addam's base critical hit rate by a percentage (additive). The strength of this effect is based on the rarity of the accessory. Unlike other accessories equipped by Addam, this effect will not affect Mythra and Minoth.
While equipped with this accessory, Addam fully resists the Doom debuff.