The concept is of course massivly creepy. Everyone has nightmares of beeing chased, of teleporting enemies, and most of all the "do not look back!" thing.
Scares the shit out of me even thinking about it.
The thing is, that in the game it is most likely to be simply anoying. What does "look straight at" mean? Do you have to look at it for some time or is the effect instant? if it is, and you stand on a tower and scan the landscape, you will have five of them at you at once.
And then what? A monster near you is not scary, because you will just beat the crap out of it. and having to do so because they become unavoidable is just a nuisance.
I like the idea, but not for this game, where mobs are only scary if they can damage your buildings. Who really cares about one more ingame death?