Came up with a bit of backstory for them, added it to their original post, but I'll put it here too!

They're 18, and short due to their species. They're very timid and tend to rely on their friends or their boyfriend in social situations. By contrast, their werebeast form is a lot more aggressive.

They're 18, but only a first-year in NRC, because of a lack of formal education. When their unique magic and were-curse first manifested, it happened anytime Ewe lost control of their emotions, so they and their family ended up isolating. Ewe has a much better control over it now, and now a transformation is only forced on full moons, so they were allowed to attend NRC. But their upbringing has the side effect that they're very shy and timid around anyone they don't know well. They only really open up after getting to know someone. They're also fairly socially inept and anxious because of the aforementioned isolation. But they open up a lot when they make friends with Ace and Deuce. And the rest of the twst boys!

Here's how their appearance changes between books. Book 1-3 three is their basic look. Book 3 is their first big win, so they gain quite a bit of confidence from it. Their horns also grow in a bit more, and their tail gets fluffier. After Book 6, they hit a growth spurt, and some of their wolfish traits show up more. Their tail grows into a wolf's tail (the base shape is still the same, just fluffier, so it resembles a wolf's tail.) Their hair grows longer and shaggier, too. Their teeth sharpen and their pupils slit. Their horns grow just a touch longer to their full length.