Hm, I was using a Darkrai lead too up until recently, using Focus Blast instead of Spacial Rend for coverage... Anyway, the suggestion I'll give is the same reason I stopped using Darkrai lead. You only get to sleep ONE Pokemon, and Darkrai can outrun a lot of the tier's biggest threats. Sure, it's fun to get a sweep going early, but there are a lot of other Pokemon that can do that -- on the other hand, being able to quickly remove a huge threat later on in the game with Darkrai is much better. In that case, since Darkrai relies on Focus Sash quite a bit, I'd suggest trying to get Forretress somewhere on the team, or a new lead that can stop Rocks from being set up. Since Deoxys-S exists, he'd probably be the only legitimate choice there, and he has enough offensive power to actually get a mini-sweep of his own going. Then again, you already have Deoxys-A. And Forretress is bait for Giratina, which is never good. Anyway, I'm really new to Ubers, so take my advice with a grain of salt I guess.