At one point, Manuel joined the Cohort and actively helped Zara with her plans, in exchange for something that was promised to him upon its fruition.
In 2012, Manuel was part of the team sent by the Scholomance to search for the body of Malcolm Fade and the Black Volume of the Dead. With Zara, Diego, and several other Centurions, they stayed at the Los Angeles Institute during the duration of their assignment. Once, he tried to convince Emma Carstairs to join the Cohort. Emma gave him a low kick in response and called him a fascist.
Upon the appointment of Zara's father as Inquisitor, Manuel stayed in Idris with Zara and Samantha Larkspear where the power they would gain in the aftermath of Annabel Blackthorn's chaos would be strongest. He soon became a Gard officer.
Manuel can be deceitful, able to pretend to be favorable to gain someone's trust. He is also sadistic and enjoys torturing others. Manuel is somewhat not committed to the cause of the Cohort but agrees and goes along with its goals of suppressing Downworlder rights as long as he expects to gain something from it.
- According to Cassandra Clare: "Manuel does have a role to play in Queen of Air and Darkness! He and Valentine share a penchant for cruelty, but Manuel doesn't have the kind of charisma and leadership skills that Valentine had, nor — and this is central to his relationship with Zara — does he share Valentine's conviction." "... Zara is annoyed that he doesn't care. Manuel isn't a believer in the cause of the Cohort; he's a person who saw a schism forming among the Nephilim and decided to throw his lot in the with side he felt was most likely to win. The side whose victory he personally could benefit the most from." "It's implied [in LOS] that Manuel enjoys torture—which is indeed evil!—but Zara doesn't disapprove of him for enjoying torture, she disapproves of what she perceives as his lack of moral conviction and commitment to her cause. So the question is, which do you think is more evil? The evil that believes in its evil cause? Or the evil that doesn't believe in the cause, but goes along with it for personal gain?"