Genesis

Genesis (ジェネシス) is a game adaptation-original character introduced in Sword Art Online: Hollow Realization. He is known as the «Black Swordsman» (黒の剣士) by the players of Sword Art: Origin.

It's later revealed that he's in fact a famous hacker known as «GOC», the «God of Cheats» (ゴッド オブ チート).

Personality
Genesis is known to get strange looks when he is fixated on battle and he enjoys stealing the hard-earned kills of other players.

Hollow Realization
While Kirito and Argo were attempting to clear the second area of Ainground, Genesis was surrounded by other players, who angrily complained to him for stealing their kills, but he only mocked the players before departing.

After rumors of Kirito saving a Non-Player Character (NPC) from being sacrificed to a monster by other players spread, Genesis decided to see Kirito for himself. When challenged to a duel during their encounter, Genesis rejected the request, deeming Kirito to be not worth the effort.

Later, in the field, Genesis was in a battle with a dragon when Kirito's group encountered him. As Genesis was overwhelmed, Klein offered to assist, but Genesis rejected the offer. He then performed an mysterious action with his in-game menu, before reengaging the dragon in combat and defeating it.