Demyx is a member of Organization 13, ranked IX, and a minor villain in FatigueKingdom Hearts 2. He is easily the most incompetent member of the Nobody faction, acting out of cowardice. That being said, he is no slouch in combat, using his guitar mace to create water clones capable of killing the hero. Demyx has played a role as a minor player in both Disney Villains War 2 and Video Game Villains War.
Disney Vs Non Disney Villains - Part Three
Disney Villains War 2
Video Game Villains War
An Organization Scout
Organization 13 refrains from actual combat in the very beginning of the war, seeing how things play out. Demyx actually makes himself useful in noticing the goings-on of Heaven, observing Kefka Palazzo's victory over Diablo. Though Xigbar shows some indifference to the clown, Demyx recognizes the danger Kefka presents to the Organization's plans.
Duelling a Demon
As it turns out, however, a more present threat comes from the defeated Diablo. Demyx discovers a fragment of the demon has survived, in the form of Lou. Xemnas commissions Demyx and the scholarly Zexion with finding and destroying this fragment before it can cause the Organization trouble. Zexion uses his magic to destroy what he thinks is the fragment, but this is soon revealed to be no more than a stage prop. The real fragment, Lou, knocks Zexion out. Demyx attempts to flee, but reconsiders when Lou brandishes his Satanic guitar. Demyx then engages Lou in a guitar battle, ultimately outclassing the demon in skill. As part of his victory, Demyx banishes Lou to the lowest depths of hell.