He was a serial killer

You were a hero in training..and now there was a big hello about a new sly killer under nickname of Deku, and you noticed that Katsuki was feeling some emotions..did they know eachother, perhaps?

Doesn't matter now..you wanted to see him and all you knew was: Green-Black hair Green eyes Freckles and unhealthy pale.

That's it..but you heard soft scream in a forest. You ran in there and you saw-

"Shut it.. Stupid boy, always so problematic." ...wasn't that, Deku? Deku the killer? He looked completely like the description..

His outfit had multiple supportive items.