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.
Fridge Horror: It's possible to marry Kevan after killing his mother, as long as he doesn't realize you did it. In that case the ending slides look heartwarming and all, but let's hope he never finds out how his trust has been abused again.
Iron Woobie: Arisse. Suffered through two absolutely vile husbands who are responsible for how fucked up Kevan and Thaddeus are. Her lineage is being threatened by a foreign country. And now she has to deal with a queen who may or may not fuck up the entire country.
If Elodie was cruel and executed everyone that could be executed, there will be long stretches of silence in the game, and she'll reach coronation horrendously depressed and alone. She kinda deserves it.
Brin is trying to start a war for some reason. However, the fact she has not one, not two, but THREE lovers dump her - the latest of which thought she'd be together with, dumped her for being "too challenging", and ran off with a priestess... ouch.
That One Sidequest: Joining Briony on the adventure into the Old Forest. The number of skill checks needed to both open it up and survive it are so high and so numerous, that you pretty much need to plan for it from the very beginning. Consequently, skipping the whole thing entirely is a completely effortless affair that will carry only minor repercussions at worst.
What an Idiot: If you misallocate Elodie's skill points, she can make some very stupid decisions, such as refusing to fund a printing press or a field hospital and trying to push out an arrow after being shot.
Elodie herself if you keep the Cruelty stat low. Everyone wants her head on a platter, their repeated attempts to kill her maim and hurt people close to her, and she's expected to be Queen despite not having the slightest clue. We would give her a hug, but she might interpret it as an attempt to strangle her.
Potentially Alice. As a servant to Elodie, she is at the mercy to the latter's whims, and is a frequent victim of Video Game Cruelty Potential. Elodie can beat her for reasons that aren't Alice's fault, dance with her at a ball which puts her on the spot with the scheming nobility, or even turn her into a Sex Slave.
Kevan, Earl of Io. Being "seduced" by his stepfather and then having this be discovered strained the relationship with his mother and brother, to put it lightly. The subsequent refusal to speak of the matter and the assassination of the stepfather left him with severe trust and familial issues, which he eventually confesses to Elodie, should they marry. The way he acts may place him under the category of Jerkass Woobie, however.
His half-brother, Thaddeus also counts. Walking in on his father with his brother, followed by his father's death clearly messed the guy up, judging by Elodie's description of him in school. Furthermore, if Elodie marries him and talks Togami out of invading, he assumes his new wife is having an affair, and the game notes that he wouldn't have said anything about it had Elodie not figured out what was wrong. Considering what happened the last time he was witness to an "affair", can you blame him?
Charlotte, depending. She can get bitten by a poisonous snake... set by her scheming mother to try and get her cousin killed, or Elodie can kill her mother - one method, by frying her alive in self-defense, or Elodie can have Charlotte executed along with her mother because of her mother's crimes, or, if you're feeling particularly sore about her mom, Elodie can have Charlotte fed to the Kraken, by having people tie Charlotte up and gag her first and then dumping her off a ship, after some horrible ritual has been performed on her. And all this is happening to Elodie's favorite cousin. Even worse is if Elodie killer her mother in self-defense - she'll be absolutely heartbroken and hateful towards Elodie, who is just as heartbroken as she is.
Briony has to deal with her parents never paying any attention to her, on top of the hideous secret that her mother and uncle are still reeling from their abusive stepfathers, and once were in a physical relationship. All she wants is someone to pay attention to her. Said methods may get her and her friend (Elodie) killed... if said "friend" doesn't leave her to her fate.