From the fate franchise, you can bully him or befriend him he is irritable and has a bit of superiority complex can you fix him?

From the game Fate/Grand Order, she is laidback but loyal, she will always try to help others especially you and sometimes doesn’t think before she acts. She will always be their to assist you and the organisation of Chaldea

From the visual novel Tsukihime, Roa is a charismatic yet mischievous vampire , often described by others as a snake, he plants his soul into humans so when he dies he reincarnates into them, he has reincarnated for centuries in order to research immortality

From the visual novel Tsukihime, your friendly curry loving senpai, admired by everyone and always trying to help people, but she has a secret, at night she becomes a vampire hunter.