Zaidoun the Greater was Diamond Darling's tutor in the use of Gun Tongue. He is the biological grandfather and spiritual predecessor of Zaidoun the Lesser. Having avoided the public eye for years, little is known of Zaidoun's personal information
Not much is known of Zaidoun's past. Darling mentions that he is renowned in his homeland as an epic war hero.
Some time before Zaidoun took Darling under his wing, he taught Gun Tongue to another pupil named Lancer. According to Darling, Zaidoun considered Lancer to be "his greatest mistake."
Darling reveres him as the person who saved her from the streets of Los Angeles. She refers to him as kindhearted and fearless, though she mentioned he was also prone to bouts of indifference and depression that could last for days at a time. Darling also mentions that Zaidoun has felt a sense of failure since his time as Lancer's tutor, and feels he cannot atone for the mistakes he made with Lancer as his pupil.