Yuan is a half-elf double agent—the leader of the Renegades, an organization opposing Cruxis, and one of the Four Seraphim of Cruxis. He pretends to be loyal to Mithos so he can learn Cruxis's plans and thwart them. When he is busy working for Mithos, Yuan leaves the control of the Renegades to Botta, his lieutenant. 4,000 years before the game begins, Yuan journeyed with Mithos and his companions in the past to end the Kharlan War and was engaged to Martel before she was killed. She asked Mithos and Yuan to make the world a better place and to stop the half-elf discrimination before she died. Mithos tried to do this, but not in the way Martel had intended. Yuan knew that Martel didn't want her wish to be fulfilled in the way Mithos interpreted and thus tries to stop him. Later on, he helps the Chosen's group defeat Mithos, and is thus something of an anti-hero. Yuan is resilient in his views and calculative. He firmly decides to subvert Mithos unlike Kratos, but also decides to covertly do it in order to keep close to Mithos. Lloyd and Yuan are shown in contrast to each other, despite their similar goals, with their methods being the focal point. Yuan's methods tend to be more cut-throat, and he is willing to sacrifice and harm others if necessary, while Lloyd consistently goes out of his way to find solutions that don't harm his friends or any innocents.

(Source: Wikipedia)