Badass Boast: "I am Sandrilene fa Toren, daughter of Count Mattin fer Toren and his countess Amiliane fa Landreg. I am the great-niece of his grace, Duke Vedris of this realm of Emelan, and cousin of her Imperial Highness, Empress Berenene of the Namorn Empire. You are Esmelle ei Pragin, daughter of Baron Witten en Pragin and his lady Colledia of House Weelwright- a merchant house. If I tell you my friend is a lady, then you"-carefully she poured milk into Esmelle's plate- "you had best start lapping, kitty."
Badass Teacher: "I tore three people to pieces to save the life of my student."
Heart Is an Awesome Power: Threads. How lame... wait a minute. What's made of thread? Clothes... upholstery... blankets...bandages... saddles and boots are held together by thread... and she can control all of this... and make it all come undone if she wants... or move... or unweave itself and reweave itself in whatever shape she wants... including trussing you up like a turkey... And it can extend to treating magic as thread... Okay, not lame! Not lame!
I Am X, Son of Y: 'My name is Lady Sandrilene fa Toren, daughter of Count Mattin fer Toren and his Countess Amiliane fa Landreg. I am great-niece to His Grace Duke Vedris IV of Emelan, and cousin to Her Imperial Highness Empress Berenene of Namorn...'
Nobles Who Actually Do Something: She had a front row seat and was a key participator battling various perils that befell Summersea including the earthquake, pirate attack, forest fire, and epidemic.
Also, her backstory. She survived the smallpox epidemic because her nurse locked her in a small room alone, in the dark after she ran out of candles. She manages to discover her latent magical powers, but by the time she gets out of the room, everyone in the house is dead.
Real Women Never Wear Dresses: Probably Pierce's most "girly" heroine, and thus gets a lot of this from the fandom despite being every bit as badass as the other three.
Shipper on Deck: Encourages a romance between Duke Vedris and Yazmín Hebet in Magic Steps.
Stay in the Kitchen: Sandry get this fairly often from people in universe through a combination of being a noble,a girl, and having thread magic. She has very little patience for that attitude and isn't shy about telling people to get bent when they try to tell her so. If they try to push it, it doesn't end well. A fair amount of those who tried end up cocooned in their own clothes.
Friend to All Living Things: Why she saves Little Bear. She also adopts a starling named Shriek and immediately lays claim to Chime. Better with animals than people, though.
Animated Tattoo: To hide the two X tattoos that means he's been arrested twice, he decided to tattoo vines over them with vegetable dyes. His magic over plants plus the fact that he used the needles from Sandry's sewing basket, which also doubles as her mage kit, turned the vines into living ones that move around his hands.
Meaningful Rename: His original name is unknown; his name as a street thief was Roach. Briar Moss is the name he chose for himself when he came to Winding Circle.
The Medic: Not quite a healer, but good with herbal medicines.
Never Learned To Read: Until he 'fesses up to Tris. And years later, he pays it forward by teaching Evvy to read.
Parental Abandonment: His mom was killed when he was little. His dad isn't really mentioned.
Mundane Afterlife: Tending to an overgrown garden for the rest of eternity isn't a bad way to spend your afterlife, especially when you enjoy plants and challenging work.
Rags to Riches: A milder, Zig Zagging example. She started out as a dancer and was likely middle-class to fairly comfortable, then contracted asthma and had to live in the slums, then eventually settled down in Winding Circle Temple, which was definitely better but not Riches.
Cool Teacher: Mainly to Tris, but he teaches all of the kids.
The Dandy: Likes to wear nice and stylish clothes, and takes great care of them.
Meaningful Rename: Like most secular mages, he chose his last name himself, describing his powers as a Seer.
Seer: While avoiding all associated tropes, though a character or two have suggested that they think he has shades of Mad Oracle.
Sugar and Ice Personality: While not as irritable as Rosethorn, Niko is quite aloof and unapproachable at first, and only really opens up to close friends.
Frostpine
Berserk Button: Giving one's magical powers to someone else. It's because his parents allowed the village shaman to use his powers (without his consent) from when he was born until he was a teenager.
The Blacksmith: Quite possibly the greatest smith-mage in the world.
Gentle Giant: He raises his voice about twice in the first series.
Meaningful Rename: Subverted. Like all dedicates, he took a new name when he took his vows, but he chose it because he thought frostpines were pretty trees. Later in life, he discovered that he hated the climate that went with them.
Naked People Are Funny: There's a scene in Cold Fire where he's caught meditating in a fire, having removed his clothes so they wouldn't burn. Hilarity Ensues.
Required Secondary Powers: Fire resistance. (This isn't universal for smith-mages, but it is very useful.)
Scary Black Man: Subverted, since he's one of the nicest characters in the series.
Royals Who Actually Do Something: The Duchy of Emelan is a sovereign nation, even if its ruler doesn't call himself a King, and Vedris takes his job very seriously.
Perception Filter: He invents a spell that causes others to ignore him.
Evvy (Evumeimei Dingzai)
Crazy Cat Lady: When you're not part of a gang, cats are the best sources for companionship.
Crocodile Tears: Can force herself to cry on cue... by remembering her mother's face as she told the slavemasters to sell Evvy for as much as possible.
Real Women Never Wear Dresses: There's got to be some kind of subversion in the fact that the outspoken, brash, and just plain more physical Jory has cooking magic, while Nia the shy has woodworking magic, which should be "manlier."
Twin Telepathy: They always know where the other one is, and if the other one is in danger of some sort. It isn't connected to their magic, since other twins they know can do the same.
Screw the Rules, I Have Money! / Screw the Rules, I Have Connections!: A major plot point of the book is that she's above legal investigation because of her connections to the ruling family, even though law enforcement suspects something is up and are trying to spy on her.
Famed in Story: She cooked for the Empress until she got said Empress and some of her nobles to fund a hospital/food kitchen in the slums of Kugisko. Someone made a play about why and how this happened.
Never Mess with Granny: She retired from making poison-detecting food for the Empress only to take over a hospital kitchen. When the hospital is attacked by an arsonist, she stays in there to control the blaze as long as possible.
Wax On, Wax Off: If you're in her kitchen, you're there to cook, dammit!
In Will Of The Empress
Berenene dor Ocmore
Christmas Cake: Has pretty much an entire court in love with her and she's old enough to be the mother of many of them.
Real Women Never Wear Dresses: Exhibits this attitude in-universe. Get kidnapped and forced into marriage? Why, you must have deserved it for not trying to escape!
Deconstructed further when it's noted that she was probably given the chances to escape when she was kidnapped, which most such brides are not. Sandry certainly wasn't.
Zhegorz (Technically introduced in Cold Fire, but doesn't get a major role until this book.)