It's a nova rainbow... unupped. If there's no supernovas, why does it work? No idea.
Notes: Even though it works for strange reasons, it's still an unupped nova deck. Therefore, don't expect it to magically beat every deck you come across.
Edit: Towers can be unupped for obvious reasons. I'm pretty sure that it's because of them that the deck works; they provide some backup in case your novas fail utterly to produce quanta (They usually do.)