This story will be very interesting story to write its gonna be very difficult to write so please be with me for this
Alzack is lore wise the 3rd born son of adam the first man and lilith the wife of lucifer
He was very close to his older brother abel when cain killed abel Alzack, snapped and brutally beat cain almost to death. Cain's blood seeped into alzack's skin into demonic symbols,
After this alzack wandered the world of yggdrasil until he met ulbert alain odle and joined Nines own goal and later ainz ooal gown and created cz2128.