Yuan Ka-Fai

Yuan Ka-Fai is one of the main support characters in Tales of Symphonia. In the game, he serves as a temporary antagonist, but helps the party later on by offering them Rheiards as a means of transport. Although he is cold and cynical most of the times, he sometimes shows a little more emotional side of himself, especially when talking about his past.

Kharlan War
Four thousand years before Tales of Symphonia's events, Yuan was one of the four heroes of the Kharlan War, along with Mithos Yggdrasill, his older sister Martel and the human Kratos Aurion. Apparently, he was engaged to Martel, though not much information is revealed in the game, although his past is more specific in other spin-ofs, like Tales of Symphonia: Dawn of the New World, Tales of Fandom Vol 2, etc.

Forming Cruxis and the Renegades
After Martel was killed near the end of the war, Yuan, along with Kratos, helped Mithos create Cruxis, the Desians and the Church of Martel, becoming one of the organization's Four Seraphim. However, Yuan secretly disagrees with Mithos's ideals, because he understands the meaning of Martel's last words: to end discrimination for all races, not only for half-elves. To fight back against the evils perpetrated by Cruxis, he created an organization known as the Renegades. His troops are often mistaken for Desians throughout the game. Yuan keeps his role as the Renegades' leader secret in order to get to know Mithos’ plans better and thus stop them if they are too extreme.

His second in command as the Renegades’ leader is a man named Botta, who dies after Rodyle succeeds in flooding the Remote Island Human Ranch to allow Lloyd's party to escape. Yuan shows no sadness when he hears the news, but it is likely that he grieves for Botta in private, as he is not the kind of person to show emotions in front of people. Yuan has learned not to grow too attached to people, perhaps because, with his Cruxis Crystal, he will outlive everyone he knows. He usually comes off as cold, aloof, and sarcastic, although he truly is one of the game's protagonists in the shadows.

Tales of Symphonia: Dawn of the New World
Yuan returns in the sequel, though has a minor role now than in the original game. He is wearing a more standard outfit, indicating that he is no longer in charge of the Renegades.

Troubled Hearts
The party first meets him in Asgard without learning his true identity, and he tells Emil and Marta that it is in fact his original hometown. He can also see Tenebrae, even though he has made himself invisible for the moment.

Eternal Bond
Later, at the new World Tree, Yuan reveals that he was helping Lloyd in his quest to prevent Ratatosk from destroying mankind. In the two years since Tales of Symphonia, Yuan has disbanded the Renegades and become the solitary guardian of the new World Tree, possibly in order to be closer to Martel.

In Emil's last visit at the World Tree, Yuan is receiving a final communication from Kratos, just before Derris-Kharlan leaves communication range and enters the far reaches of space. Although Yuan and Kratos first started out disliking each other at the first game, they address each other as true friends in their final address. When Tenebrae mentions Kratos’ voice, Yuan asks him not to say anything to Lloyd.

It is notable that Emil and Marta never find out Yuan's role in the first game, neither as angel of Cruxis nor leader of the Renegades.

Tales of Fandom Vol 2
In Tales of Fandom: One Other Symphony, Yuan is shown traveling with Mithos, Martel and Kratos in their original quest to revive the Great Kharlan Tree. It is revealed that he joined the group in order to 'expose his hypocrisy,' and thus tends to argue with Mithos and be teased by him, Martel and Kratos. However, even at this point, he is in love with Martel, and often complies when she asks something of him. At this time, the party is closely knit, and Mithos often wonders why Yuan does not simply tell Martel about his feelings.

IF Kratos chooses to have Yuan with him in the Gaoracchia Forest, it will also be revealed thatthey used to be enemies before (Kratos was in the Tethe’alla’s army, while Yuan was in Sylvarant’s). Yuan tells that he used to hate Kratos because Kratos never hated him. Instead, he was always apathethic to people he met.

Fighting Style
Yuan has four thousand years of fighting experience, and is skilled with his double-edged weapon, sometimes called the Swallow. He can also use angelic spells, though never uses it in battle against the party in the game, and his magic is primarily lightning-based. Although he can fight on par with Kratos, when Mithos reveals his presence in Altessa's home, he easily defeats him with magic.

His two most powerful mentioned attacks are Thunder Explosion, and the spell Indignation. In the Japanese PS2 version, Yuan has new techniques, including a more powerful aerial version of Volt's standard "Strike" move, and a stab attack that launches the target into the air, not unlike some of Regal's skills.