What is more terrifying?

WisTrit, was I talking about imps or demons?

Okay ;)
But the units are still demons too...

Arthas, as undead, isn't stupid and pointless, because he was actually striving to become King.

And in Disciples, it seems that demons were also originally on another plane of existence, and only a small group of them were on Earth. And they were trying to bring Bezresen out into this world...
And they are still trying...