I see really scary Smeargle>Physcial Lucario passes in the near future.
Arceus is illegal for a damn good reason-it is just too plain motherfucking broken for ubers, a tier that is already unbalanced to an extent.
Though it would be near impossible to stop a +6 Extremespeed Arceus.
Umm, it's banned because you can't get it in-game yet. If something's too broken for ubers, then why the heck would it be called ubers?
I did some calculations, and a +6 Arceus CAN still be stopped, since it still doesn't OHKO a 252HP/252Def +Nature Giratina with Shadow Claw. That means that it can come in after something's dead and Will-O-Wisp to neuter Giratina. (Heh, there's always a Bulky Unaware Bibarel than can do it too, but yeah).
Arceus is illegal for a damn good reason-it is just too plain motherfucking broken for ubers, a tier that is already unbalanced to an extent.
Though it would be near impossible to stop a +6 Extremespeed Arceus.