Abandon Shipping: Sans/Toriel a.k.a Soriel was getting some traction, as the two seemed to grow closer in their side-plot and even went on a date together. However, fans jumped ship pretty quickly with the reveal that Sans only befriended Toriel to get information out of her. While some shippers still hold out hope, the very antagonistic way Sans interrogates her made most of them give up on the notion of them getting together romantically in the comic.
Audience-Alienating Ending: The comic ends on a cliffhanger, as the SOUL disconnects from Kris in order to free them and stop the Knight's plan from coming to fruition. Many fans were turned off by this ending, finding it to be a cop-out that doesn't work well in a non-interactive medium.
Fridge Horror: In the room with Noble and Naughty, the last pair of options are "One of you is a terrible person." and "One of you will destroy your home.", where the party has to select the truth between the two in order to answer correctly. Susie chose the former, which is the false option. But that means the latter option is true. Out of all the ones in the room (Kris, Susie, Ralsei, Lancer and Irales), who will destroy their home? What home are they concerned about? Is it the Lightner world, the Darkner world, or... something else? And how would they destroy it?
Harsher in Hindsight: Noelle coming into her own power in the Dark World thanks to Kris encouraging and guiding her is a heartwarming moment in the comic. Come chapter 2 of the game and you have the option of doing something very similar in canon - only it's anything but heartwarming. The so-called "Weird Route" is achievable by steadily egging Noelle on to use her powers in a lethal way. The end result is Noelle becoming an obedient killing machine, haunted by a Compelling Voice that can follow her even to the Light World.
Jerkass Woobie: Susie is an overly antagonistic bully towards almost everyone who isn't Kris and she can even be a real pill to Kris when the two of them are alone. But underneath all that posturing and unpleasantness lies a lonely girl who is so scared of being rejected that she decided just not to try to make friends at all. Apart from that, she's also so convinced that she is a horrible person that she just can't believe Noelle, a genuine Nice Girl would ever be interested in someone like her.
Kris, when you really think about it. They're a lonely kid with only a handful of friends, two of which are only Living Toys and to top it off, their parents have divorced fairly recently and their big brother is almost never in town. Adding onto that, the comic frequently hints at them not really having the best childhood before the Dreemurs found and adopted them. Oh, and they're regularly possessed by a mysterious entity against their will and have no way of telling anyone about it.
Noelle. Her father is in the hospital because of an unspecified illness and it's heavily implied her mother is neglectful and/or overly demanding. She has a major crush on Susie, but can never seem to tell her either because she just Can't Spit It Out or because circumstances seem to actively conspire against her. Adding insult to injury, she frequently sees Susie wander off with Kris, with the two of them even getting caught in the closet together. Kris at least manages to dispel her fear of them and Susie having gotten together and with her becoming the Sixth Ranger, there's a good chance she'll finally manage to confess to Susie.
Lancer, especially later on in the story. He loses his entire kingdom and all of his subjects due to a freak accident and is forced to go into a coma-like state every time Susie takes him out of the Dark World. Even though he seems to take all of it in stride, the fight with Seam reveals he's deeply insecure about his own role in their adventure and his inability to fend for himself. It gets worse when the Fun Gang enters the Dark World in Noelle's house, where the former Spade King ended up and Lancer's former soldiers try to stab him in the back because their fear of his father is greater than their loyalty to him. The fact that the only reason they don't fight the Fun Gang is out of apathy rather than a change of heart doesn't really help either.
Susie. Sure, she often resorts to violence and intimidation towards most of her classmates, but that's because she thinks it's better if people stay away from her and get scared of her, for it's the only way she thinks they'd respect her. The truth is that she thinks she's a horrible person, because she suffers from Horror Hunger, which makes her constantly want to eat everything around her. And that's because she suffers from malnutrition, since she couldn't afford the carnivorous diet that she needs due to her family's poverty. Oh, and her grandmother that she lives with often scolds her for complaining that she's still hungry. Susie's all alone in this suffering, and the worst part is that she didn't know that her needs are different than others all the time. You've gotta feel bad for her breaking down when Noelle revealed how she actually needed that diet all along.
