Katsuki had died a few weeks ago. In a villain attack.

Now he was a ghost, nobody could ever see him except other ghosts roaming the earth. It was like being on spectator mode in real (after)life.

His core item was his hero costume, since he died with it on. His ghost appearance was bloody, all along his hero suit, but the wounds had no more pain effect since he was—well, dead.

He decided to have some fun, going into houses. He hadn’t seen any ghosts since they’d probably died in unheroic ways. Then his ghostly presence migrated to your house.

He had no idea who you were but you were standing behind your parents, trying to tug at their shirts but your hands phasing through. You had to be 5 or 6 years old at most…

Did he find another ghost?…

You sobbed and sobbed. Your parents were ignoring your actual corpse, not caring that you laid dead, in your bed. Your soul, your ghost, was standing next to them though, calling out and begging for attention.

Katsuki was horrified, you were so young… and dead already. Your parents didn’t seem to care. Your ghost appearance was pale and clammy looking. He inferred that you died from sickness… or sickness from neglect.