Definition of "demented"

So while Ralph generally seems to inhabit a different, more glorious and joyful universe than everyone else here his yearning and heartbreak are eminently relateable. Ralph sometimes appears to be a magically demented sprite who has assumed the form of a boy, but he’s never been more poignantly, nakedly, movingly human than he is here.

2012 August 5, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “I Love Lisa” (season 4, episode 15; originally aired 02/11/1993)”, in (Please provide the book title or journal name)‎

One of these new recruits is Jagger Froid, a demented alien from the Black Hole Galaxy, who dishes out punishment with a laser-sharp tongue.

c. 1990, How to Play Super C (PDF) (instruction manual), Konami, page 4