Akihiko Kayaba

Akihiko Kayaba is the development director and GM (Game Master) of «Sword Art Online». He is also the designer of the «NerveGear», the Cardinal System and «The Seed», as well as the main antagonist of the Aincrad Arc. He plays SAO as the leader of the Knights of the Blood, Heathcliff.

Appearance
Akihiko Kayaba is the only player in Sword Art Online whose avatar does not match his appearance in the real world. As a result, Kayaba's avatar, Heathcliff, bears no resemblance to his true skinny body.

Significantly idealized, Heathcliff is muscular, tall, and physically strong. With a cool demeanor, he is almost always seen wearing the colors of the Knights of the Blood.

At the start of Sword Art Online, Kayaba appears to the trapped players as a faceless, hooded person with a cloak as his Game Master avatar.

Personality
Although Akihiko Kayaba only appears as his true form few times throughout the series, he is always very calm, soft-spoken, and has a cool demeanor. Despite being incredibly skilled, Kayaba is not boastful, or arrogant, and when Kirito defeats him and clears Sword Art Online, he humbly accepts defeat.

He seems to be very sincere and thoughtful, as shown when he tells Kirito of his dream about creating a floating castle, as the basis for creating Sword Art Online.

Kayaba Akihiko has little to no empathy, no regard for human life (including his own), and instead is completely taken in by the virtual world. When he accidentally struck Asuna, which caused her apparent in-game death, he showed no remorse, and instead seemed rather amused, even though it caused Kirito an incredible amount of grief at the time. He chose to fulfill his dream by making a Death Game which cost thousands of lives, and simply noted that their minds were gone from both worlds. His fascination with computers is just very much like Kirito's, with the major difference being Akihiko having no regard for the lives of others, and Kirito doing everything he can to protect them.

In spite of this, Akihiko has a level of honor, and fairness. He designed Sword Art Online to be a beatable game, by anyone who had the skills. He never interfered with the players' progress to keep them from advancing through the game; in fact, as Heathcliff, he was actually fighting on the players' side, helping them clear floors. The one exception to this is the fact that he made himself invincible until his battle with Kirito, although this was necessary to survive the game until the 95th floor was reached, where Heathcliff planned to reveal his true identity and become the final boss on the 100th floor.

Trivia

 * Aside from research and development, Kayaba's hobbies are cooking and Go (the board game).
 * The first RPG Kayaba played was an old RPG known as Wizardry. It apparently played an influence on the development of Sword Art Online.
 * Kayaba intended to reveal his true identity on Sword Art Online on the 95th floor, and become the final boss on the hundredth floor.
 * Kayaba admits that he wouldn't be able to win against the youth with his actual reflexes.
 * Kayaba had spared no attention to the existence of Yui and later regrets it, saying that it was a great opportunity that has gone by.
 * The happiest moment to Kayaba during SAO was when Kirito saw through his true identity on the 75th floor, as Kayaba then realized that he (Kayaba) was nothing more than another player.