It takes a very specific type of person to get scouted as a WW2 codebreaker and then decide that doesn't involve enough violence for her taste and go do something more dangerous instead.

Charismatic, skilled at hands-on mechanical/combat type tasks, low end of species literacy, very poor impulse control, prone to latch very hard onto people who credibly display signs of caring about him as an individual.

Personality very significantly mutable by environment.

Even when there's two of them, they're in some ways more like one person in two bodies than like two people, really. This is why it's such a bad time when there is, in fact, only one.

Based on Lily Evans Potter from HP universe.

unusually large for species, ideally winged, usually female, longer lifespan than family if possible, optionally very big fluffy dog; the paladiniest paladin who ever paladined