From Halopedia, the Halo wiki
Inslaan 'Gadogai is a mysterious, short-tempered Sangheili blademaster serving the Keepers of the One Freedom. He was a veteran of the Silent Shadow during the time of the Covenant, before rebelling against the High Prophet of Truth and Tartarus' Jiralhanae leadership at the onset of the Great Schism. By 2559 he was a mercenary serving the Banished as an eye for Escharum, before leaving them in favor of Castor and the Keepers of the One Freedom. Following the failed attempt at firing the Halo Array, he and Castor were left as the only survivors of the Keepers of the One Freedom.
In the Covenant, Inslaan 'Gadogai served as a blademaster in the Silent Shadow. Following the Massacre at Eridanus Secundus, 'Gadogai saw the Chieftain of the Jiralhanae Tartarus present three remaining slipspace crystals to the High Prophet of Truth in the Inner Sanctum. Soon after, 'Gadogai would eventually rebel against the High Prophets and their new Jiralhanae leadership at the onset of the Great Schism.
Stabilizing the Banished on Reach
At some point in time Inslaan 'Gadogai joined the mercenary organization known as the Banished. 'Gadogai served as an eye for War Chief Escharum on Reach, to report if Legionmasters Deukalion, Ballas, and Castor were focused on the mission.
Defection to the Keepers of the One Freedom
When Atriox arrived at Reach on a Lich via portal from the Ark, Inslaan 'Gadogai failed to block Castor and his Keepers of the One Freedom from boarding the Lich after Atriox and his crew exited it. Atriox ordered 'Gadogai to kill Castor and his Keepers for betraying him, to which 'Gadogai ignored and betrayed the Banished in turn by escaping to the Ark with the Keepers. Castor welcomed 'Gadogai as an official member of the Keepers of the One Freedom as they flew through the Portal back to the Ark.
Personality and traits
Inslaan 'Gadogai has developed a pattern of short-term relationships with factions, moving from faction to faction over time.
Skills and abilities
As a former member of the Silent Shadow, 'Gadogai has a seemingly preternatural degree of strength, speed, and agility - even for a Sangheili. At the Ark's Epsilon Spire, Inslaan moved with a hand speed far too great for the Dokab Castor to notice; snatching a communications disk from the front of the latter's belt, in spite of the Jiralhanae's alerted state. Notwithstanding his comparatively slender frame, the Sangheili was also considered a match in strength for Castor; a feat highly unusual in contrast to their species. 
When faced against the Ferrets, notably the Gammas attached to the team, an unarmored 'Gadogai was swift enough to reliably shove and elude the unarmored Spartan-IIIs before they could realize they had been attacked. In the moments they could finally start their weapons towards him, the ex-Silent Shadow member had already vanished from sight once more.
Toward the Control Room Access Balcony at the Ark, Inslaan contemplated his chances against the unarmored yet adrenaline-surged Ash-G099 and Olivia-G291, with a fairness towards his odds of survival - even when armed with just a hard-light glaive and the Ferrets trained on his vulnerable body with their MA40 assault rifles.
According to the ex-Silent Shadow member himself, this level of physical prowess was only possible as a result of his purchase of a mysterious energy which permeates all living beings in the universe.
List of appearances