Do Percy Jackson and Annabeth Chase end up together?

Annabeth tells Luke as he dies that she always saw him as a brother, but never loved him. Later, she and Percy share their second kiss after she tells him that she will never, ever make things easy for him. ... Then comes a third kiss underwater in an air bubble made by Percy. They are together at the end of the series.

Did Annabeth kills Percy?

Heroes of Olympus/Magnus Chase Sickfics - Annabeth kills Percy.

Is Jason Grace stronger than Percy Jackson?

No. Percy Jackson is, first of all, older and more experienced. Percy will do whatever is necessary to keep friends and loved ones save, resulting in more boldness in combat. Percy is a better swordsman than Jason.