These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Taig (and by extension Cailet) vs. Geria. It's so satisfying to see the snooty First Daughter taken down a peg.
Crowning Moment of Funny: There's a lot of humour with Sarra finding out just who is in the Rising in the first book - including a scene in a bower where she nearly starts a brawl (she punched someone who offended her), and then realizes that who she thought was her target was actually someone completely different...
In the second book (set about 16 years after the first), Collan goes to a bath house to work out, and tries to act like it was easy as pie... and then promptly doubles over when he gets a back twinge. That's not even counting all the times he and the other men in the bath house get jealous when the male prostitutes come in (they're paid to look the best they can be).
Newer Than They Think: Creation of Ladders is a long-forgotten art, thought lost since the Waste War - but a number of them are probably newer than that, some possibly only decades old.
The wraithenbeasts - and Anniyas becomes one and has a lot of fun being as vicious, cruel and horrific as she can be, including murdering a mother wildcat and then watching as her cubs starved to death.
What Anniyas did to Bard Falundir - cut out his tongue and sliced the tendons in each finger.
The effects of Wild Magic. One young girl has it, and her family describes being in terror of not knowing what she'll do next, including a description of her being utterly devoted to her kitten one day... and then ripping it apart the next.
Glenin. Sweet baby Jesus, Glenin. Thinks nothing of mindraping and brutalizing her own family, puts a spell on her husband so he'll be devoted to her (and only her) - which gets him killed when he tries to follow her through a portal and gets ripped apart, tortures and murders Collan... It just never ends.
Tearjerker: What happens after Cailet is brutalized by Glenin - her own sister.
Gorynel Desse's death - actually, pretty much all the deaths, especially Collan's.
Cailet being shunned by Taig after she is made Captal. He was her first love, and it's heartbreaking to watch him completely change his behaviour around her.
The fact that both Sarra and Glenin lost their First Daughters - Sarra through miscarriage and Glenin through involuntary abortion.
The young boy (Toman) in The Mageborn Traitor who goes mad with Wild Magic and attacks Cailet at first seems like a simple case of Nightmare Fuel. Then you come to find out that he has five other children (including two of his older sisters) that have been living in his head for the last six years. Turns out he was out for a picnic with a bunch of his friends when he was very young, and they all got swept away by the river. While their bodies died, their minds were inadvertently magically sent into Toman's mind, where they proceeded to accidentally drive him mad. The worst part is, it isn't even Toman's fault, it's one of his friends whose magic was so powerful she united all of them in a moment of unconscious fear, and because Toman himself wasn't Mageborn, he had no idea how to handle the power and it went all screwy.