I think that 1st thing that needs to happen is to remove target cap from this skill.
https://eso-skillbook.com/skill/aspect-of-terror

If you look at Aspect of Terror and its morphs, pretty much all you get is increased target cap with one morph and 2x target cap with the other morph.

In comparison, Turn Evil (fighters guild skill) has no target cap, and on top of that it grants 2 minor buffs - not only for you, but also for your allies.
https://eso-skillbook.com/skill/turn-evil

Aspect of Terror, simply put, lacks additional effect, and was obviously not "standardised" at all as it is probably the only AEO effect left in a game that still has a target cap.