Actually the nightmare of the guardian(yes, that is our canon name) is very unique. It isn’t really the enemies we face, but rather, the guardian has no nightmares. Remember in the storyline, we are unique to no other. The darkness won in every timeline until we came on the stage. So we have no nightmares because we are just not afraid. We’re the most resilient of all guardians, which is why you have people headbutting a sword wielding maniac who glows blue and is a hive god. Who else does that?!