“You disgusting sacks of flesh!”
Doctor Struktor was a mad scientist interested in some secret “power” the party possesses. He was secretly a warforged supremacist working for an unknown “Lord”.
His weapons of choice were a magical auto-crossbow that can split bolts, or a magical force crossbow which generated it’s own ammo.
When revealed as a Warforged, he sprung blades from his body, which he could use to stick to walls or shred his opponents.
His final act was to activate the Colossus.