WTF kind of class is this!?

Character Introduction: Part 1 (written by Chess)

Name: Nekoma Taichi/Taichi Nekoma
Appearance: Dark grey hair and tales, black eyes
Abilities: Can shapeshift between human form and (two-tailed) cat form. He's good at hand-to-hand combat. Mostly attacks with scratches, though.
Personality: Naive, pure (as in he won't understand any innuendos even if they were dancing naked in front of him) and adorable
Background: Taichi is the adoptive brother of Sakurada. He was her accomplice in her later crimes which does not include the murder of the onmyojis that killed Sakurada's biological family.

Name: Ulrick Fredderick Ottoman (UFO)
Appearance: Black eyes, silver hair and really light green skin.
Abilities: Super strength due to the Earth having less gravity than his home planet. He also has a small flying saucer which has incredibly destructive powers.
Personality: Cheerful, naive and extremely protective of his friends.
Background: Crash-landed on Earth, Destructo's backyard to be specific. UFO quickly befriended Destructo who later convinced him to destroy a city together.

Name: Destructo Evans
Appearance: Dark hair, brown eyes, slightly sunburnt skin
Abilities: He doesn't exactly have supernatural abilities but he does have a giant hammer with extraordinarily destructive powers that are out of the norm.
Personality: Aggressive but protective of his friends.
Background: He's just a human boy from a normal human family who really really wants to destroy things and somehow ended up with a definitely supernatural hammer of mass destruction. When an alien named UFO crashed into his backyard, he became friends with him and later convinced said alien to destroy a city with him... For fun.