Lavi

✎General
✒  Strongest interest is in history, but really he likes learning of just about all kinds. Math is probably his least-interesting subject.
✒ The question "why" in regards to negative human behavior--he really doesn't get it, and while he's usually good about keeping an emotional distance and not caring and neutrality and etc this one question really frustrates him. He can see everything wrong with what they do through his objective, observing lens and it doesn't make sense why they can't too and not do it.
✒ On some level he's starting to have that question answered with his own behavior since becoming an Exorcist and getting entrenched in the Order, but he's in denial about it. There's still a sense of superiority regarding other people when they fuck up.
✒ He doesn't fully change personas between records. His name changes, and the role within the record might change (such as becoming an actual solider), but he doesn't completely shift personalities. Not that he can't act effectively, but he usually makes use of an identity similar to Lavi--it's friendly, effective, and keeps people from guessing at his motives when they're not supposed to know. With people who are aware of the functions of the clan, he generally drops it in favor the cold and aloof behavior that's been nurtured from his work.
✒ Becomes surprisingly easily attached to genuinely good people. Those like Doug and Allen that are giving and kind and optimistic challenge all those pessimistic views of humanity he was fostering, and he's attracted to this behavior.
✒ Bitter as they make him, Lavi has a strong interest in war history above other types. Battles and generals and events and inventions and holy/unholy and all that good stuff, because they're mostly the "secret history" he spends his time recording.

✎Sexual
✒ Is a virgin still, but he has has sexual encounters. Light things like flirting, kissing, probably some groping and making out. Very infrequent, and usually as a result of letting his facade get out of hand and/or experiencing some sort of frustration (usually in relation to the things he sees on the job, humans suck and blah blah blah--he's been asking the question "why" a lot earlier than Lavi). Bookman probably smacked him around when he caught him doing this.
✒ However, there was no attachment and he had no intent to go further, so he was still able to drop them like they were nothing and move onto his next record. This also probably kept punishment from being too severe.
✒ Normally, though, he represses this behavior. He doesn't generally masturbate, and when he does it's pretty clinical.
✒ Aside from his perverse remarks and being touchy-feely though, which are more staples of his persona, he hasn't actually done anything like that in his time at the Order.
✒ Is reasonably book-educated about sexual taboos/sexual functions--mostly because it's knowledge and why not, and it's not like while traveling he never saw things.
✒ Has a crush on Lenalee. Not in love with, but a sense of admiration and gosh she's pretty. He's in denial about this because of the whole issue with attachments.
✒ Likes curvaceous women--those who have well-sculpted bodies all around. He also likes shoulders for being the area of the body that's the most chiseled, no matter weight or muscularity. Also legs.
✒ Straight. There's room for exception if he can develop the emotional attachment but really he's attracted to women.
✒ If Lavi were to ever have sex, it would start out the least sexy thing because he'd be worrying about protection and comfort and CAN WE REALLY RISK A PREGNANCY (I guess that's not a problem if it's a guy but then there's also issues like anal sex sounds painful if you don't know what you're doing).
✒ Would probably want to either read a book or take a nap post-sex.