Dallan Morvis served as the second-in-command on the Courageous throughout the duration of the Mandalorian Wars. He participated in combat operations at Vanquo, Serroco, and Omonoth. Subsequently, he received a promotion to captain, assuming command of his own capital vessel, the Veltraa. Ultimately, Morvis achieved the rank of admiral and was granted leadership of the Diligence.
His father established the Coruscant Financial Exchange, and his mother held the position of senator representing Chandrila, indicating that Dallan Morvis was clearly prepared for significant achievements. However, instead of the expected enrollment in the Naval Academy on Coruscant, Morvis opted to become an asset within the Admiralty.
Following his graduation, he began as a junior liaison connecting the Vanjervalis design team with the staff of Admiral Noma Sommos. This assignment eventually resulted in his advancement to lieutenant and his initial assignment to the bridge of the Reciprocity, serving under the command of then-Captain Saul Karath. Morvis recognized Karath as an emerging leader and chose to follow him to the Courageous, directly into the Mandalorian Wars. Yet, aboard the Courageous, Morvis encountered a rival in the form of junior officer Carth Onasi. Onasi shared Karath's humble origins and a tendency for swift, sometimes imprudent, decision-making—qualities not found in the well-bred, calculating Morvis. Morvis perceived Carth as a competitor for the admiral's favor and actively sought to complicate his life.
When fugitive Padawan Zayne Carrick was brought aboard and later joined their escape from Serroco, Morvis displayed no compassion for Onasi's newfound companion. Nevertheless, it was Onasi and Carrick who saved Morvis from a potentially career-ending catastrophe aboard the Arkanian Legacy. During that incident, Morvis proposed to Karath that the Republic employ exogorths—weaponized space slugs capable of destroying entire star systems—to establish a firewall of devastated systems between themselves and the Mandalorians, even suggesting negotiating for Republic control over the slugs. However, Onasi and Carrick brought the affair to an unfortunate conclusion, leaving Morvis empty-handed back on Coruscant.
This time around, Morvis decided to leverage his political affiliations, which not only allowed him to avoid punishment but also secured him a captaincy aboard Karath's subsequent vessel, the Swiftsure, and eventually, command of his own capital ship, the Veltraa. Consequently, Morvis continued to demonstrate his resilience as a survivor, prepared to do whatever it took to safeguard his position—a subtle aspect of Karath's character that he struggled to emulate and foster. He eventually became Zayne Carrick's commanding officer during the Mandalorian Wars, and both were captured by the Mandalorians. Eventually Zayne took charge during a prison escape, and the rest of the soldiers began to defer to Zayne. Morvis was enraged and blamed Carrick for everything bad that had happened. Zayne finally had enough and told Morvis that it was his own fault; now that he was in a position where he couldn't rely on favors he didn't know what to do. Morvis finally broke down and admitted that he felt the need to live up to his family's proud legacy. Zayne told him that being a hero meant facing danger when the time came.
Ultimately, Morvis was elevated to the rank of admiral and granted command of his own Inexpugnable-class ship, the Diligence. Millennia later, the mercenary brigadier Jarrow Rusher described him as a competent yet misunderstood officer. Sith Lord Arkadia Calimondra, however, asserted that his achievements were based on deception.
In a sequence of posts on Twitter, John Jackson Miller established connections between various clues within published works that allude to the future actions of Dallan Morvis and Zayne Carrick.