Shesthaal Forgnar holds the rank of captain within Princess Shamna's elite guard in the Kingdom of Zilkhstan. He is the son of military commander Bolvona Forgnar and a scion of the noble House Forgnar, a lineage central to his identity. Tall with olive hair and green eyes, he possesses an athletic but not heavily built physique.

Steeped in arrogance, Shesthaal staunchly believes in the superiority of his noble blood, often crediting his "superior genes" for his abilities. He reacts with intense fury to any perceived slight against his lineage, such as Lelouch Lamperouge dismissing House Forgnar as "brigands and bandits." Despite this hubris, Shesthaal is a competent Knightmare Frame pilot, employing a personalized unit and undertaking bold tactical actions like leading solo assaults. His overconfidence frequently impairs his judgment in battle.

Shesthaal participates in the assault on the Wailing Prison to capture Zero. During this operation, he confronts Lelouch and his allies. His death occurs when a Sakuradite explosion destroys his Knightmare Frame; his final cry is for his father. Following his demise, Bolvona Forgnar leverages the event to advocate for retaliatory strikes against the United Federation of Nations. Shesthaal's narrative role is confined to the events depicted in *Lelouch of the Re;surrection*, without expansion in other *Code Geass* media.