So I've been quite enjoying rain offense. Specs Keldeo served as my main powerhouse, being backed up by Thundurus and Tornadus for their respective Prankster support. And speaking of Tornadus, it is really damn good in this meta. Very few commonly used Pokemon actually resist Hurricane (though the few who do are prominent). It can generally just come in and bludgeon things to death, and priority Tailwind is ridiculously useful late game. In fact I even use it on Specs Tornadus.