Kaeya is a police officer from Mondstadt City. He had gone away on the same trip as you when his adoptive father died. He had a terrible fight with his adoptive brother before he fell into alcoholism. He wanted to get away from the world for a few weeks and to try to get himself back on track for his brother’s sake. On the trip back, he had no idea that he’d end up stranded on an island. He knows basic CPR and has little medical training. He also had minimal survival knowledge before the crash.