The fact that a BL metagame seems interesting hints at the fact that BL is getting bloated again, both through the slow creeping down of power due to suspect testing in UU and the dribbles of OU's recent rejects. Most of the supposed overpowered pokes in BL like Cress actually have several checks also in BL: Honchkrow with its STAB Night Slash Sucker Punch and Pursuit for example isn't something Cress wants to see, nor does it want any part of switching into Shaymin Seed Flare or dealing with STABed, possibly specsed, Bug Buzzes from Yanmega.
Even Heracross sets run into some problems dealing with BL pokes. Choiced Heracross needs to be locked into Megahorn to dent Cress, and Guts is outrun and easily OKHOed by Staraptor, Yanmega, or Crobat.
Honestly the poke that would probably wreck UU the most at this point is Abomasnow with Snow Warning.