Since when are undertale songs copyrighted? I always use the soundtrack and some other remixes that are fanmade While I know some of the remixes may have copyright on them I know the UNDERVEIL Soundtrack was free to use as long as credit was given? (It's spanish but you get it)

That's really weird. I used bonetrousle on a YT video I made about two years ago, never got any copyright notice or whatever for using it. You should be able to get it sorted I hope.

Also Materia Collective LLC really does not sound real.