Well, physically, they could inherit Percy's athletic build and Annabeth's height. Their hair could be a dark shade, perhaps with a bit of a wave from Percy, and their eyes might be a mix of green and gray, taking after both parents. They would probably have a confident and determined look in their eyes, much like their parents.
In a fanfic, their child could look quite unique. They may have Percy's messy hair, but in a lighter shade due to Annabeth's influence. Their eyes could be a piercing green, and they might have a smattering of freckles across their nose like Annabeth. Their overall appearance would give off an air of both strength and intelligence, which are the hallmarks of their parents.
In the fanfiction, their kid could have a look that reflects both their parents' natures. Since Percy is associated with the sea, the kid might have a sort of 'ocean - like' charm in his or her appearance, like wavy hair. And from Annabeth, the kid could inherit her intelligent and sharp - eyed look. Maybe the kid has a tanned complexion like Percy from all the time spent outdoors at Camp Half - Blood.
In this fanfic, Percy could develop a darker side. The horrors of Tartarus might make him more ruthless when it comes to protecting himself and Annabeth. Annabeth, on the other hand, may become more empathetic. She could see the pain and suffering of the other beings trapped in Tartarus and try to help them, which would shape her character in a new way. Also, their relationship would develop further. They would have to trust each other completely, and this could lead to a more mature and deep connection between them.
Annabeth might be initially speechless. She'd look at Percy with a mix of disbelief and love. After a moment, she would throw her arms around him and say 'yes' while laughing. She would then start thinking about all the adventures they could have as a married couple and how they could build a future together in both the mortal and demigod worlds.
Percy might develop more of a steely determination. In Tartarus, he has to face extreme danger, which could make him even more resolute in protecting Annabeth and getting out. Annabeth, on the other hand, could become more resourceful. She'd have to use her wits in this strange and deadly place.
Their relationship in the fanfiction could develop in a more mature way. College is a time of self - discovery, and they would be no exception. Percy might become more confident in his abilities and be more assertive in the relationship. Annabeth could become more empathetic towards Percy's insecurities. They could also start planning for their future together, like thinking about post - college life and how they can continue to fight for the good of the demigod world while also having a normal life. Maybe they even consider starting a demigod training program for future generations on their own.
It could be common. Considering how important Annabeth is to Percy in their story, he might be eager to explore more about her through fan - written works. However, it also depends on Percy's personality. If he is the type who likes to stick to the original story only, then it might not be so common. But if he has an open - minded attitude towards different interpretations of their relationship, then it's likely to be common for him to like Annabeth fanfic.
Percy would probably feel a mix of shock and confusion at first. He might wonder why Annabeth left him with this huge responsibility. Then he would start to feel a bit scared because he doesn't know if he can take care of the child properly.
In the long run, Percy might grow from the experience. He could become more cautious in his relationships and less trusting. Or, if there's a chance for redemption in the fanfic, he might be open to forgiving Annabeth if she shows true remorse and has a valid reason for her actions. But initially, it would be a very difficult and emotional time for him.
Well, they might inherit Percy's sense of humor and his loyalty. So they could be the type to crack jokes in tough situations and always be there for their friends. They might also have Annabeth's intelligence, being quick - witted and able to think their way out of problems.
They would probably be very affectionate. Annabeth might rest her head on Percy's shoulder while they talk in hushed voices. Percy would likely have his arms around her, holding her close and giving her a sense of security.