@ZiggyPulsardust I think it's both a touhou refrence and refrence to the song, but I agree it will not be used in Deltarune. Interestingly, Penumbra has been used in homestuck even after deltarune so toby isn't opposed to using the lemotifs still.
I think the nymphs starting off as adorable innocent little blobs and then by the end of their lives morphing into eldritch abominations is pretty telling of roses outlook on growing up and adulthood