Yeah, Deoxys-S/Xurkitree using Zap Cannon are what makes me think that it should be banned. Against Deo-S, you have to switch-ins except Groudon, Zygarde (hoping it doesn't run Ice Beam), Blissey (which can be broken through with Nasty Ploy and Focus Blast), Zapdos, or some really bulky mons...