I know Timid gives me ice beam, Dragon pulse, Flamethrower, and surf to use for great coverage. Jolly gives me an amazing D-dancer with Dragon claw, and E-quake, and Brick break/extreem speed.
I would say the Physical attacking Rayquaza,Deoxys-S is a big threat in Ubers and it requires Priority to beat,since Priority is rare in Ubers,also it would make it a great revenge killer.
I would go with jolly because most/all of the tomid move sets are tms so if you don't like any moves just give it tms so I would use the jolly nature hoped this helped