Ouran Nakagawa

Ouran has a very erratic personality, usually saying things that make little sense, such as enslaving all humans or turning all weapons in the world into sweets. In the flashback arc, it is revealed that Ouran originally had a much more mild personality, acting calm and shy, but upon befriending Kadode, she became more happy and confident. More or less of her personality reflects a toned down version of the alternate timelines Kadode. Her erratic behavior being heavily influenced due to her coping with Alternate-timeline Kadode's suicide.