In the past I used Specially Defensive Scizor as a defensive pivot with Palkia, and as a revenge killer for Darkrai (after Sleep Clause) and slightly weakened Deoxys-A. Bullet Punch didn't OHKO, but Deoxys-A rarely carries HP Fire, allowing Scizor to beat it easily. It served my team well, especially when I was using Arceus-Fighting, but I've since replaced it with Arceus-Steel, who beats the Extreme Killer (Scizor was walled by it), is far bulkier, and can actually take unSTAB Fire Blasts.
However, if your team can't use an Arceus, I would recommend Scizor. It beats a pretty wide variety of Ubers, such as Mewtwo without Fire attacks, Deoxys-A without HP Fire, and Darkrai once Sleep Clause is activated. Arceus can only beat Deoxys-A by switching to a strong physically defensive Pokemon (like Groudon) to sponge the Superpower, then switch back in to kill Deoxys-A. Scizor doesn't have such trouble with Deoxys-A.