Kayaba Akihiko, known as Heathcliff in Sword Art Online, was the main antagonist of the Aincrad Arc and a supporting character in the Fairy Dance Arc and Alicization Arc. He was the development director and Game Master (GM) of «Sword Art Online», as well as the designer of the «NerveGear», the Cardinal System, and «The Seed». As his avatar Heathcliff, Akihiko eventually founded what later became Sword Art Online's strongest guild, the «Knights of the Blood». He was the owner of the first «Unique Skill», named «Holy Sword», and was considered to be strongest player in-game. He wielded the collective one-handed sword and tower shield called Liberator. He also was able to engage the boss of the 50th Floor in battle for ten minutes by himself, which earned him the title «Man of Legend». It was also rumored that Heathcliff's hit points (HP) had never reached the yellow zone. Kayaba Akihiko wore a white shirt with a necktie underneath and a long, white lab coat on top. The contours of his face were fine and sharp. He had metallic eyes and short hair. Kayaba Akihiko was the only player in Sword Art Online whose avatar did not match his appearance in the real world. As a result, Heathcliff, Akihiko's avatar, bore no resemblance to his true skinny body at all. Significantly idealized, Heathcliff was muscular, tall, and physically strong, with sharp scholarly features and steel-gray hair that had a strand hanging over his forehead. He was almost always seen wearing the colors of the Knights of the Blood, though the background and foreground colors were reversed. At the start of Sword Art Online, Akihiko appeared to the trapped players as a huge faceless, hooded person with a cloak as his Game Master avatar. Although Kayaba Akihiko appeared as his true form only a few times throughout the series, he was always very calm, soft-spoken, and had a cool demeanor. Despite being incredibly skilled, Akihiko was not boastful or arrogant, as when Kirito defeated him and cleared Sword Art Online, he humbly accepted defeat. Akihiko seemed to be very sincere and thoughtful, as shown when he told Kirito of his dream about creating a floating castle as the basis for creating Sword Art Online. Kayaba Akihiko had little to no empathy, with a complete disregard for human life, including his own, and instead was 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 was 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 had 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 was 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.