Balmung, also referred to as Lord Balmung and "Balmung of the Azure Sky", is a legendary player in The World. He gains his title by defeating an event called the One Sin, which was thought to be unbeatable, with his partner, Orca, causing them to be known as "The Descendants of Fianna." He is a Blademaster, who is given white wings after the event as a reward. He can use them to float and jump higher than other players. Balmung is originally very formal and assertive of his views, following a strict moral code of doing good in The World, leading some to consider him arrogant or rude at times. He truly loves The World and takes playing it very seriously, to the point of investigating disturbances within it personally and refusing to speak with .hackers or associating with them. In .hack//Legend of the Twilight, he's much more carefree and less serious with new players, though still completely business-like with his associates.

Balmung is one of the Descendants of Fianna and is a very famous player in The World.