Mostly, I'm trying for things that are simple, but we don't see too often. Auras reattaching isn't anything new. It's just that this guy has something specific in mind, and asks people "how would I build around this?". It's a good anti-pacifism player if nothing else.

Reminds me of Bruna, Light of Alabaster, which is Mythic Rare. Of course, a similar ability is seen on Simic Guildmage. I think this might be more sensible if it only moved one aura.
That said, this isn't really something either black or white does mechanically, is it? But it does seem like something they might like to do philosophically, and for different reasons.

It would be more sensible. That's why I chose not to do it. More interesting this way, if you ask me.

White does this: Glamer Spinners, Kitsune Mystic. Black certainly doesn't, though. Green would be my next colour for it, putting this in the slot for a creature with a activation. On the other hand, it does feel odd for a white creature to be grabbing all the funky stuff for itself; the ability has a little selfishness to it, which is black. Hmm.

To me, attaching all auras should be rare. If this just stole one aura per activation, I'd like it a lot better for uncommon.

Done.