The High Prophet of Regret, born Lod Mron, was the youngest of the three San'Shyuum High Prophets who led the Covenant High Council during the Human-Covenant War. Rash, ambitious, immature, and naive compared to the other Hierarchs, Regret originally served as Vice Minister of Tranquility, where he worked frequently with Sangheili and had adopted some of their personal traits, such as a preoccupation with honor and personal arms.
In many ways, he can be characterized as a Prophet who thought like an Elite; a rare mindset for his species, and from the Prophet of Truth's point of view, a dangerous one. Regret was intelligent and fiercely opposed humanity through the course of the war. He expected his soldiers to obey him without question.