She could be heartbroken. Annabeth has been through a lot with Percy, and to be rejected for Rachel might make her feel like all their adventures together meant nothing.
Annabeth might initially be angry. She's a proud and strong character. In some fanfictions, she might lash out at Percy, feeling betrayed. But later, she could also grow from the experience, realizing that she can't force Percy to love her and focus more on herself and her own growth.
One reason could be that Rachel represents a different world to Percy. She's more of an outsider to the demigod world, and Percy might be attracted to that sense of newness and freedom she seems to offer. Maybe he's tired of the constant danger and drama in the demigod life with Annabeth.
Annabeth could also be angry, not at Percy but at the situation or the forces that led to his death. She might vow revenge and start on a journey to find out who or what was responsible for Percy's sacrifice and make them pay. This could lead her into a whole new set of adventures and challenges as she tries to come to terms with her loss.
She might be heartbroken at first. She could try to jog Percy's memory by showing him things that were important to them.
Then, she would probably be angry. Annabeth is a strong - willed character. She would feel betrayed and used, and her anger would fuel her to find out the truth. She might start her own investigation to figure out what's really going on with Percy, whether he's been influenced by someone or if there's another reason for his actions.
Annabeth could be shocked at first. She might not have expected Percy to be so straightforward with his feelings. She would need a moment to process what he's said, and then she might respond in a more measured way, like asking him some questions to make sure he's serious.
He could also become withdrawn and depressed. Percy and Annabeth have a very strong bond, and her death would leave a huge void in his life. He might isolate himself from his friends and family, lost in his grief and memories of her.
She'd probably be shocked at first. But then her face would light up with joy. After all, she and Percy have been through so much together.
It would definitely strain Percy's relationship with Annabeth. Annabeth would likely feel betrayed and confused. Their long - standing friendship and the romantic feelings they had for each other would be shattered. As for Percy's relationship with Reyna, it would become more complex. They would have to deal with the fallout from Percy's choice, not just from Annabeth but also from their friends and the overall demigod community.
Annabeth might be initially in awe of Percy's new godly status. But she would quickly start thinking about how to use this new situation to their advantage. She is practical, so she would likely start planning how they can better protect their friends and the world.
On the other hand, she could try to honor Percy's sacrifice. Annabeth might focus on the reasons why Percy died for her and strive to fulfill any tasks or goals that he might have hoped she would achieve. She would carry on his legacy in a positive way, even though she is heartbroken.