That was the right kind of sweet. Very nice! I like the shining sun Wolfram part at the end. But I've got to say that the following is my favourtite line of all:

"...his face full of two parts hope and one part promise of violence if Yuuri dared to impugn his artistic talent yet again."

So Wolfram. And that as you've potrayed here is the kind of relationship I'm sure they have. And what an interesting one too!