Comet could beat Homelander, Omni-man, Superman and Saitama. And thats because she more on the level of Bugs Bunny or The Mask. Even without her horn Comet can manipulate reality beyond what anyone could comprehend. Her collection of per-written spells isn’t just cutsie growth spells, she has some terrible disturbing crap in there as well. She can control fire, time, animals, etc, Comets writes illegal spells for her friends all the time. She has domain over the night sky (really space but The Stars sounds cooler) You can’t actually kill her in any way that matters because she’s already an anomaly spawned from the stars as a consequence of magic overuse(all unicorns are) and barely counts as alive.

And Comet is still pretty chill. Try to kill her and she’ll view it like a wild animal doing what wild animals do but keep doing it and they’ll become “inside-out man” I’m dead fucking serious.