Basic Trope: A villain reported to be powerful, ruthless and exceedingly evil turns out to be disappointingly feeble
Straight: The hero breaks down the door to Baron von Ruthless' chambers, only to find him to be an old man in a wheelchair.
Exaggerated: Baron von Ruthless is bedridden and on life support.
Downplayed: Baron Von Ruthless has a leg cast.
Justified: Despite his brilliant mentalabilities, Baron von Ruthless has cancer.
Inverted: Baron von Ruthless is infamous for his mental abilities rather than his combat skills, but manages to put up an impressive fight against the heroes.
Baron von Ruthless' infirmity was all an act and he attacks the hero.
Baron von Ruthless may be stuck in a wheelchair, but it turns out he's still a powerful sorcerer who can put up a fight through sheer magical power, skill, and willpower.
The vaguely human-shaped mass of steel plates and spikes from earlier, who our heroes "learned" was a body double upon encountering the feeble old man before them, really was Baron von Ruthless, and the old man is just there to get would-be assassins to drop their guard while the real Baron von Ruthless closes in.
Only to find out that this Baron von Ruthless was a robot. The real one has been dead for years.
The "real" Baron von Ruthless was working off a script, and our heroes' initial assumptions about the old man were correct.
Parodied: Baron von Ruthless has committed several heinous crimes and is wanted in several countries. It's revealed that Baron von Ruthless is actually a genius 10-year-old child working all of it from behind her computer.