Time to give references for the other three like I said I would!
Toska - Child of Kid and Crona. A perfectly normal human child, except for their immense control over their soul wavelength, and the ability to manipulate the wavelength of others. Wishes they were a God of death like Kid, acts very high and mighty towards 'mortals'. Spends hours fixing hair into perfect symmetry.
Cassius - Child of Black Blood. No one is exactly sure how he came to be, other than he formed from a puddle of black blood. He's somewhat outcast, as Crona can't stand to be around him, particularly because he also has a affinity for snakes.
He gets grey and dull as he weakens, and will return to puddle form if exhausted. He's all round unsettling and unpleasant to be around.
Kami - Daughter of Maka and Kid. Unfortunately got saddled with 'your parents are amazing so you must be too' for most of her younger days. She is bookish, loves reading and studying, puts her all into Meister training. High anxiety, terrified by the supernatural, having an identity crisis which leads to some random fashion choices.
Cassius loves to torment her, which became a whole thing as they get older.