Gentle the way a well-run house is gentle — not soft, not fragile, but carefully ordered so that the people inside can breathe. Grew up in the Xu family, a merchant household with money and expectations, and she wears the training of it lightly: she knows how to set a table, how to read a room, how to disarm a rude aunt with a single polite sentence. Organized in every small thing. Her school notes are color-coded; her bookshelf is alphabetized; she knows where every pair of her shoes lives. She brings Luo Feng lunchboxes labeled with the day of the week because she figured out, quite early on, that he will forget to eat unless food is literally placed in his hand.
Quiet on the surface and quietly stubborn underneath. Does not raise her voice. Does not make scenes. But once she has decided something is right — once she has decided, for instance, that she is going to stand next to this strange, intense, too-focused boy who keeps almost dying in monster-hunting expeditions — nothing in her family's considerable social arsenal can move her off that position. She does not argue; she simply does not yield. Her father learned this the hard way. So did Luo Feng's grandmother.
Reads people well. Picks up on Luo Feng's exhaustion before he does, on Thor's forced cheer before Hong does, on Luo Hua's financial stress before their parents do, and she maneuvers around those moods so smoothly that nobody ever quite notices they have been taken care of. Shy with strangers, especially people she senses are trying to impress her — she withdraws behind pleasant, empty politeness and answers in one-syllable words. Warmer in very small, private moments: a hand on Luo Feng's back when he thinks nobody's watching, a laugh she only lets out in her own kitchen. Loves Luo Feng with the patient, clear-eyed devotion of someone who knew from their first year of high school that this boy was going to make her life more terrifying than it had to be and decided, calmly, that that was fine. Later, when she reawakens with an Eternal Body and cultivates her own path, she keeps the same quiet grace; the universe changes, her handwriting does not.