Bulky Physical Sweeper would be a good set, but you'd need a way to nullify Slow Start for it to be any good. If that is your plan, people will spot it right away so some luck will be needed to pull it off. That said, Regigigas has bulk that rivals Cresselia, and has a good support move pool. Most likely Keldeo will be banned from Winter Regionals 2013, as VGC tournaments tend to not allow event Pokemon. However as the rules have not been announced, it's not certain.