Ash of War: Poisonous Mist
Game: Elden Ring
This Ash of War grants an armament the Poison affinity and the following skill: “Poisonous Mist: Bathe armament in poison, and then slash, spreading toxic mist forwards. The armament retains its poison for a while.” Usable on melee armaments (whips, fists, and claws excepted).
Where to Find the Ash of War: Poisonous Mist
You can get it by defeating a teleporting loot beetle in the Swamp of Aeonia, in Caelid.