Number 128 (I think that's its name)

Any strategies for beating this boss (You find it while escaping the MagiTek armor facility for those who forgot_?

Is this the one that changes its weakness? Well, I don't think you have Vanish-Doom then (and alot of people think that's cheap, so you may not want to use it anyway..) Just scan, and hit it with it's weakness. Edgar has a tool called the Debriblator. (I know that's not the exact name, but meh.) That changes the enemies weakness. I'm not sure if you have it yet at that point in the game, though. (It's been awhile, forgive me.)

Or your talking about the boss when you're escaping on the rail-things. If you have Sabin, you should use Flame Dance, and Sword Techniques with Cyan. If you have the Drill for Edgar, use that. (Or the Chain-saw.) Or use level 2 elemental spells, which do alot. (Although I recall some of the body parts to absorb elements..) Well hopefully someone with a better memory can help you more :p

Focus on the body, the rest die when it dies. Edgar Chainsaw/Drill, Sabin Aurabolt, Cyan Dispatch/Retort and just heal whenever you need it. Should be able to handle it unless you're underlevelled.

Edit: Oh, if you can't focus on the body without his blades killing you, use Drill on the body and then use Sabins Fire Dance and Cyans Quadra slam.

What would be underleveled?

Errr...if you're having a hard time killing him :D? Sorry man, it's been years since I played it, i'm going off a very suspect memory. :D