Archdemons anyone?

[Handel]

They are random as almost any other unit. I found them when just running and exploring the demon realm. Got even to the Baal's castle and he teleported me to the center of the realm.

BTW (kind of spoilerish)...







In one of the quests you can choose which kind of troops you will be fighting against in another quest later.
A demon "recruiter" asks for an advice - which kind of mercenaries to choose for battles in the iceland. Guess who you will be fighting later