Brutus Humblebone. On the recruitment screen, you'll see that he is a swordsman with an eidetic memory, allowing him to level up quickly; but that he also suffers from insomnia, meaning that he recovers health and energy less reliably from rest.
There's a lot about him you won't know from looking at that screen. For instance: he is a narcissistic and blunt ex-novelist from Claverbush, a small town on the mainland. He grew up poor with his mother, father, and three sisters. He gets along well with his sisters, but not his parents. Brutus loves sapphires because they remind him of the ocean, and horror stories because they offer him a cathartic release for his deepest fears. You'll probably see him relax with a horror novel from time to time in the evening--but otherwise, you won't know any of this until he talks to other characters. (And because he is narcissistic and blunt, his dialogue will range from self-aggrandizing to judgmental as he reveals things about himself and his past.)
Because he has insomnia, Brutus will sometimes be unable to sleep and will try to tire himself out by practicing late at night. This will net him experience, but at the cost of energy. Because he loves horror novels, he will sometimes spend the evening in his tent, recovering morale by reading a truly frightful book. And because he is an ex-novelist himself, Brutus can undertake the "write a novel" project. This will produce occasional mini-events in the evenings describing his progress (or lack thereof). Eventually, he will complete the project and produce a usable item called Bruce's Novel, which will appear in your inventory. You can give it to a character to read to raise their morale, or else sell it for a good chunk of money.
Characters who become familiar enough with him will nickname him: "Brutie," say, or "Brutes." They'll do things together, like spar. When Brutus gets close enough to someone, he'll reveal his deepest secret: he's never felt empathy for other people. He likes to adopt different personas and push boundaries, just to see what he can get away with. Brutus likes the other character, though. If Brutus and the other character get to be really close, he will start to teach them combat skills out of concern for their safety.
Things can happen to Brutus. He might find out that his mother is gravely ill and request time off to go visit her. He might fall ill himself, hampering his ability to use special skills in combat. He might have a change of heart about being a swordsman and ask your permission to change to a new class. Another character might fall in love with him, and he might brutally reject them--or he might not, and they might go on a date.