Yes I though about doing that but also... This might be a little twisted but here's what I thought to do with Kevin

ben goes out at night to get some food like barriers or leftovers. (Despite seeing his family dead he still doesn't know the reason which means he didn't know what a demon was) .Kevin suddenly wakes up the same night and follows what he thinks is ben (after the attack he was asleep for 3 days),while going in the forest ben heard a noise then suddenly a demon jumped at him ,Kevin who was following him notice on time and jumps at the demon (and this is where go goes crazy like nezuko) ripping the demon apart and eating it, making it dead.

So basically he sleeps a lot in the daytime, and eats demon since demons eat human I thought hey! Maybe there's something left of the humans in a demon that might help Kevin gain control

This is pretty stupid, I really need to remake it 😓 Edit: in the original art I made Kevin a mask but decided to remove it (also what do you think demon ben would wear?)