Heroes 5.5 WarGame Edition - Tactical Edition.

Currently, the demons look like this (I will update the classes later):

Alastor doesn't fit in visually.
Personally, I don't have such a strong sense of style, but one of the other developers does, and therefore it is important that there are no glaring inconsistencies in the class's style.
In its current form, for example, it is very easy to determine which class a demon belongs to, even from its icon.