Kuradeel was one of the 10,000 players who got trapped in the cursed death game, Sword Art Online. He was originally assigned by his guild, Knights of the Blood, to protect Asuna. He was later revealed to be a member of the infamous PK guild, Laughing Coffin.
History
Kuradeel came with Asuna to Algade as a bodyguard. He was extermely upset when he learned that Asuna was bringing Kirito into her home, in order to cook the Ragout Rabbit. He became even more suspicious when he learn that Kirito was a Beater. He made a comment about Kirito being a beater leading an angry Asuna to order him to leave.
The next morning, he was watching Asuna's home, causing her to run away. He justified that he was started a month ago because it was a part of his duty. He forcefully grabs Asuna to go back to Knight of Blood HQ, but Kirito intervenes and stops him. Angered by Kirito's declaration of being a better protector, he challenges Kirito to a 1-on-1 duel. During the duel, Kirito uses «Weapon Break» skill, which destroyed Kuradeel's sword. Despite Kirito allowing him to use another weapon, Kuradeel admits defeat but made a comment of wanting to kill Kirito. He is then ordered by Asuna to go back to HQ and stay there until further orders. He accepts the order and than transports to Grandum.
After Kirito joined the Knights of the Blood, Kuradeel underwent obligatory training with him and two other guild members, but tried to kill Kirito by setting a paralyzing trap in the drink. He then revealed himself as a member of the Laughing Coffin PKing guild. Kuradeel then started stabing Kirito with his sword several times. When Kirito's HP was about to reach zero, Asuna reached in the scene in time and attacked him. She healed Kirito with a crystal, and continue to fight Kuradeel, easily overpowering him. He fooled Asuna into lowering her guard, then attacked her. However, Kirito had recovered by then, and he sacrificed his own left hand, (but got it back later) and defeated Kuradeeel with his Martial Arts Skill Embracer. At last he calls Kirito a killer, before dying.