Board Thread:General Discussion/@comment-37146126-20181230214133/@comment-32182236-20190101020131

Ruins is the theme of determination itself, being in both Undyne's theme and "Don't Give Up". Snowdin Town is a song about friendship, so perhaps Pacifist Frisk? Snowdin Town shares a leitmotif with the Shopkeeper theme, so perhaps it belongs to the Snowed Inn? (They DO "sell" you a key to a room, after all.)

Judging by the name, Ooo seems to be a ghost theme. The leitmotif places it in Waterfall (matches the start of the Waterfall theme). The lack of a madness motif likely gives it to Happstablook, if anyone would own it at all. (Napstablook already has one)

Quiet Water shares a leitmotif with Ruins, so it's determination.

CORE and Hotland are both contained within Death by Glamour. So Mettaton probably gets those too. He owns just about everything in Hotland nowadays.. No wonder he thinks so highly of himself.