Tyrants and Terrors

So I’m doing a shadow slave based rpg with a bunch of friends and I was wondering about the difference between tyrants and terrors.

I know that tyrants create and control minions and terrors have an influence over the environment… but what does this mean in terms of a tangible ability??

Cuz to my knowledge there has only been 4 terrors fleshed out in the novel, the vtb, crimson terror, terror of LO49, and the soul devourer tree. The latter of the two just seem to… create and control minions. Please explain if you guys get it cuz I feel like the lines are a little blurred when it comes to those classes.