Andonisus, Reaper of Souls



Andonisus, Reaper of Souls was a main hand sword designed to help in the battle against Atiesh.

Source
Andonisus was a legendary sword and drops off, a summoned demon in Stratholme which was part of the quest line. Atiesh dual wielded this weapon at the beginning of the fight and in the course of the battle dropped one sword which a player could then use against him.