Larxene "the Savage Nymph" is a major villain in Kingdom Hearts Chain of Memories. The only female member of Organization XIII she is 2nd in Command in Marluxia's rebells who command castle oblivion. She's almost always smiling and talking in an excited cheerful manner, is actually is a sadistic, violent woman who enjoys fighting, killing, toying with and manipulating her enemies (as well as her 'friends). It's suggested that she is indeed a sociopath (although she does seem to be able to feel rage as shown in her final boss fight) and doesn't even try to understand emotion which seems to be her undoing. Despite this she does seem to be friends or at least on very good terms with teammates Axel and Marluxia. Her powers are lightning based and she fights with a set of french daggers that are used in close combat, one could assume that she enjoys being close to her foes when she finally does kill them.
I wanted to give Aubrey Plaza (Parks and Rec/Legion) a good villain role since she;s been doing such a great job as crazy antagonist of FX's Legion, Lenny "The Demon With Yellow Eyes" Lenny is an out of control insane woman with a devilish grin on her face almost at all times. Lenny in her true manifestation as supernatural villain is incredibly sinister and evil and crazed. Aubrey has this down perfectly so playing Larxene would be a piece of cake for her. While the nobodies in KH are basically immortal and undead i had initially thought she was a lot younger than Aubrey is but i think it doesn't really make any difference.