Good alternate builds for the final boss (spoilers)

[Mavrickindigo]

Got friends who want to continue this campaign, but they are really powerful now. I would like the final boss to be much better, but his classes are basically trash, so what suggestions do you have?

[FedoraFerret]

http://www.d20pfsrd.com/classes/core-classes/barbarian/archetypes/paizo---b arbarian-archetypes/savage-technologist

This is what I'll be using if my party continues gaining as much power as they are. (the probably will, because I'm rebuilding almost every encounter from the ground up).

[Paladin of Baha-who?]

Savage Technologist, possibly with levels of gunslinger, would be an excellent fit for the character. Add undead blood rage powers to fit his bone-hand, maybe.