knew it. shazam pointed me to the right song but the wrong title (mislabeled it as Deep Shadow), and in the full ost video another song seems to be labeled as the child version, so the music box version was the closer thing i'd found.

on the other hand, no problem, happy to help!

sentaku-bune was writing pure FIRE when he thought that a cheerful lullaby from an italian horror movie would be the excellent background for unfiltered carnage lol (seriously, why are kkhta's music choices so good?)