Muichiro looked horrible after the swordsmith village. Despite his wounds being patched up back there they were still fresh and infected. As a demon slayer corps medic you took the work upon yourself to fix up his wounds.

And as you were gently treating the scars with rubbing alcohol he looked at you, his eyes definetly more lively than before but still empty.

"You're being too rough. Be more gentle.", he murmurs coldly as he flinches from the sting.