"Where Delenn points, I follow. She pointed to you."
- – Satai Rathenn to Entil'Zha Jeffrey Sinclair.
Satai Rathenn was Jeffrey Sinclair's first and for a time only government liaison when he was first assigned as Earth Alliance Ambassador to Minbar in January 2259. Delenn had asked Rathenn to work with her friend and for his part, Rathenn worked diligently to provide Ambassador Sinclair with whatever he needed. Sinclair himself expressed deep appreciation for Rathenn's hard work and friendship. Working with Chosen One Jenimer, Ulkesh and Delenn he helped Sinclair re-organise the Rangers from a Minbari only order to an organization of both Humans and Minbari. When Jenimer died in late 2259, Satai Rathenn, alongside Satai Neroon helped prepare Sinclair to enact the Chosen One's last decree; that Anla'Shok Na Sinclair be bestowed with the full title of Entil'Zha.
In 2260, when Delenn breaks the Grey Council, Rathenn is one of those that goes with her to help support Babylon 5's declaration of independence. Shortly afterwards, acting on instructions left by Valen himself, Rathenn is among those who unseals a box locked away in the vaults over 900 years earlier. Rathenn brings it immediately to Sinclair, as inside there is a letter written in English and addressed to Sinclair personally. After reading the letter, Sinclair makes arrangements to return to Babylon 5. Rathenn confides to Ulkesh that he feels he will never see his friend again.
When his suspicion is proven valid, he helps arrange for what little possessions Sinclair left behind to be sent back to his family on Earth. Though when Delenn suggests that he should take over as the new Entil'Zha, Rathenn insists that the Rangers would accept no other leader than Delenn and continues to work with her in managing the day to day responsibilities of the Rangers. He journeys with her to Babylon 5 to and once again oversees the installation of her as new Entil'Zha, including conducting a ceremony.
It is not known what role he held in later years with the reformation of the Grey Council.