[Overview}
Blaziken is a Pokemon one would not normally expect to see in Ubers. Its base stats show nothing exciting, save above-average attacking stats. However, in Black and White it receives the ability Speed Boost, which means that given just one turn alive, it can be a very potent sweeper. Access to Swords Dance, Substitute, Agility, and Baton Pass means that Blaziken can see play over Ninjask as a Baton Passer, due to the fact that it can actually deal damage. It is slightly let down by mediocre defenses, but a resistance to Ice and Fire mean that it is easy for Blaziken to come in and start setting up.
[SET]
name:Uber Swords Dance
move 1: Swords Dance
move 2: Hi Jump Kick
move 3: Stone Edge
move 4: Flare Blitz/ Shadow Claw
item: Life Orb
nature: Jolly
evs: 252 Atk/252 Spe/ 4 Def
[SET COMMENTS]
This set is tricky to set up but can be insanely powerful with Blaziken's ability to boosts its speed. Hi Jump Kick OHKOes many foes like Scizor, Palkia, Kyogre and Zekrom and is Blaziken's best Fighting STAB attack. Stone Edge covers most Flying types that Blaziken will face. It OHKOes Ho-Oh and Rayquaza, and is guaranteed to OHKO Lugia after SR damage. The last set depends on whether you have sunlight support from Groudon. Flare Blitz in sunlight OHKOes Groudon and 2HKOes Latias, Latios, and Giratina-O. Jolly is preferred to give as much of an edge over any potential Scarfers. EVs are needed in Speed and Attack to maximize Blaziken's sweeping prowess.
[Team Options]
Blaziken will struggle with defensive Groudon, Scarfers, and getting a chance to set up. Wobbuffet is a godsend as it can trap and kill most of them. With its annoying Encore, it can give Blaziken needed opportunities to set up. Kyogre can TWave Latios, Latias, and Palkia switch-ins.
[Optional Changes]
Blaziken does not have many other viable options. A mixed set is better left to Reshiram who can hit anything neutrally. Thunderpunch is outdamaged by Stone Edge and Hi Jump Kick. Protect could be used if you don't mind losing coverage. A baton pass set could be done since Blaziken is deadly to many Pokemon.
[Counters]
Physically defensive Kyogre could come in but HJK will hurt it a lot. Choice Scarfers faster than Base 80 can threaten it as well. Groudon will be a problem without Flare Blitz. Giratina and Giratina-O can be counters but have to be wary of its Shadow Claw.
Propose any additional sets. I think Reshiram would be better with a mixed set because it can hit anything neutrally.