I've wanted to do this for a while
Gender: Scailon can pass for a girl in either form, and he doesn't mind being seen as a girl
Handiness: Bin can use either hand. Tria and Scailon are better with their right.
Education level: None of them have actually went to college or anything like that. But I'm going by how smart they are and how they would tolerate school. Scailon would be happy with moderate schooling, Tria would go to college but probably get bored of it and start slipping. Bin would be pretty determined to finish if he started.
Readability: They all can be stonefaced if they want to be.
Gender Appearance: Scailon's got curves most girls would die for XD
Sexuality: Tria is Bi, but leans ever so slightly towards Hetero. Scailon is Bi as well, but leans more towards Homo. Bin is straight as an arrow.
Romantic: Tria could care less about what a date actually entails XD. But can be romantic if she wants. Bin on the other hand, he'll go all out if you let him. Flowers, fancy restaurant and clothes. Everything.
Affectionate: For Bin, only with a chosen few. Anyone else and he's NO GO AWAY XD
Disposition (Outwardly): Bin can be kinda snippy and grumpy, The other to are cheerful and kind
Disposition (Inwardly)": But he's kind at heart, you just got to get to know him better.
Petty: I don't know exactly what petty means XD so this could be off
Sane: Bin ranges on the insane side of things some time. And of course the other two will break in the right situation.
Friendliness: I can imagine Bin actually saying that XD Ew friends. Tria and Scailon are a little more open, but they don't except anyone who just comes up and asks it. You gotta put effort into friends.
Graceful": Bin can be clumsy XD Scailon is incredibly graceful
Courageous: Bin, despite his saying otherwise, is incredibly courageous.
Lawfulness: Bin don't give a shit bout rules