Around 5800 BC, Atlantis was threatened by the Faceless Ones, a monstrous humanoid race. Unable to face them alone, they accepted help from the "Unforgiven Dead". The "Dead" were a mysterious tribe from the North who posed as wise men. They defeated the monsters and in exchange their leaders became the new King and Queen of Atlantis, respectively Suma-Ket and Artys-Gran. Given power, the source of their wisdom was revealed :they were worshipers of the Old Ones (implied to be the figures from Lovecraftian works). Under their rule, Atlantis degenerated to "darkness and depravity". Human sacrifice became common place.
Kalen, a descendant of the deposed House of Kamuu, eventually led the Atlanteans to an uprising. With the intervention of Neptune himself, the rising was successful. Suma-Ket and his surviving followers were banished to the Grey Waters, a mystic prison in the borders between life and death. Artys-Gran, the last of the Unforgiven Dead, still standing was slain. Her corpse was buried in a secret location. Millenia passed and only Socus, a hybrid Atlantean-Unforgiven Dead, still wandered the seas.
In the 1950s, Atlantis was destroyed by Paul Destine. In its ruins, Princess Fen was barely clinging to life. There Socus discovered her. Pleased to find a descendant of the House of Kamuu, Socus initiated a ritual. The spirit of Artys-Gran was transferred to the broken but still living body of Fen, a slow process of magical rejuvenation beginning. Meanwhile the spirit of Fen transferred to the mummified body of Artys-Gran, giving life to the undead body. Their spirits were linked and both could speak through either body.
In the 1990s, Artys-Gran resurfaced using the body and identity of Fen. She appeared friendly to her "son", Namor. But claimed the throne of Atlantis in her own right. She used the position to release the Unforgiven Dead from their mystic prison. She also prepared to revive the cult of the Old Ones and resume the practice of human sacrifice. All the way struggling with Fen for possession of her body. Having access to Fen's memories was bewildering. She was also struggling with nightmares of her own death, about eight millennia after the fact.
Discovering what was going on, Namor prepared an uprising against his "mother". He managed to release the true Fen, now in control of Artys-Gran's original body. The threat was great because Fen now had access to the Artys-Gran's memories and could use the same magical methods. The situation was building to a confrontation between the two women. But it never occurred. During the battle between Namor's followers and those of the Unforgiven Dead, Artys-Gran was slain by Warlord Seth and Fen by Socus. Their spirits left the world of the living at about the same time.
Artys-Gran had abilities comparable to other Atlanteans but above average strength.