Another aspect of Daki fan fiction could be the alternate universes. What if Daki was never a demon? How would her life be? These are the kinds of creative ideas that can be explored in fan fictions, and they often attract fans who want to see different interpretations of the character.
If the grandfather is very warm and accepting, Shikaneji would feel relieved and happy. They might open up more about their relationship and their dreams. Nejire could start chatting excitedly about their future together, and Shinsou would relax and join in the conversation more. However, if the grandfather is not so friendly, they would be disappointed and perhaps a bit defensive.
One main element is his difficult upbringing in poverty - stricken surroundings. Another is the constant bullying and discrimination he endured due to his physical appearance. And of course, his strong bond with his sister Daki. This bond was what drove him to protect her at all costs and also influenced his actions as a demon. For example, he would go to great lengths to avenge any harm done to her because of their shared experiences of being outcasts in society.
One popular theme is redemption. Since Daki is a demon, some fan fictions might explore the idea of her finding a way to redeem herself. This could involve her making amends for the harm she has caused to humans.
At first, Sans would probably be a bit shocked, but then he'd turn on his laid - back, sarcastic attitude. He might make jokes at Gaster's expense, which could either annoy Gaster or make him respect Sans more. If Gaster tries to harm him, Sans could use his shortcuts to dodge attacks and try to find a way to reverse the situation. He'd also likely be thinking about how this affects his friends in the Underground, especially Papyrus, and try to find a way back to them.
Gyutaro was born into poverty. He and his sister Daki had a very tough life. They were constantly bullied and looked down upon. Gyutaro had a deformed body which added to his misery. He was filled with hatred towards the world that treated them so badly. In order to protect his sister, he became extremely violent and cruel to those who he thought were threats. His experiences in his early life shaped him into the demon he later became, using his powers to lash out at those he despised.
Papyrus might be initially shocked. He's used to Sans being more laid - back, so seeing him in a fight could be quite a surprise. His eyes would widen and he might gasp.
An AU fanfic is a type of fan fiction where the story takes place in an alternate universe with different settings or circumstances than the original work.
An au fanfic is a type of fan-written story that takes the characters or setting of an existing work and places them in an alternate universe or situation that differs from the original.