Diane, Serpent Sin of Envy

Diane, standing thirty-feet tall, is a 750 year-old member of the Giants' Clan from the land of Megadoza, who bears the Sin of Envy, symbolized by a Serpent symbol tattooed on her left thigh. Unlike her more violent kinsmen who make a living as mercenaries, Diane dislikes fighting. Having run away from home, she came upon King by chance, and the two spent centuries together before he erased her memories of him, and she returned to her tribe soon after.[vol. 10] She later became an apprentice of her chieftain Matrona, alongside Dolores, and accompanied Matrona when she was hired by a Holy Knight unit under the command of Gannon, who actually intended to kill the giants and make a name for himself. It ended with Matrona seemingly dying from being poisoned and slaughtering the knights with Diane ending up in Liones' custody, and falsely accused of both the knights' slaughter and killing Matrona in an act of envy. She was recruited by Meliodas before her execution could be carried out.[vol. 16] Following the Deadly Sins' disbandment, Diane hid in the Forest of White Dreams before Meliodas and Elizabeth recruited her. Diane having feelings for the former for treating her like an equal and being initially jealous whenever he flirts with Elizabeth.[vol. 1, 2] But after being impressed with Elizabeth's selflessness before regaining her memories of her time with King, Diane becomes very good friends with Elizabeth. She eventually regains her childhood memories of King and forms a relationship with him, eventually getting married after the Deadly Sins disband despite the ceremony being disrupted by the Supreme Being's attempt to bring about a new Holy War. As revealed in Four Knights of The Apocalypse, Diane bore King about seven children with their oldest being Nasiens. As a Giant, Diane is incredibly strong with a deep connection to nature which allows her to manipulate the earth with her race's ability Creation. Diane retains her strength and agility.

Diane's sacred treasure; Gideon, is a war hammer designed for the Giant Clan. It is made of a material that is stronger than steel and weighs approximately 2,200 pounds. It is able to draw out the full capability of her ability, Creation.