Acerbus was raised in a tribal culture, bears ritual scars around his mouth, was enormous even as an Astartes, unusually courageous for a Night Lord, wielded a great power axe, served among the Kyroptera and was the youngest of Curze’s captains. He openly desired to become Curze’s heir, later ascended to daemonhood, commands the largest known Night Lords warband and believes fear is an end rather than merely a tool. In M41, he answered Sahaal’s call on Equixus, tried to claim the Corona Nox and tore off Sahaal’s arm during their confrontation.