Udayana Exion dis Nyack was a member of the Kege'la Order under the command of Teishen during the Prothean Reaper War. She was a powerful biotic who had received preliminary training under the Imperial Special Forces before the Prothean Reaper War. She was on a mission when the Reaper attacked the Citadel, so she was spared, and later on managed to rejoin the Flaruniss Fleet established by Vahana.
She joined and served in the Kege'la Order because it shared similar nature with her former service. She had never spoken of her experiences of her former status as a member of the Special Forces other than to Teishen and Vahana, as it was Classified matters.
Although the Kege'la Order and the Hari Order had different tasks and different purposes since their establishments, the two military groups had always been in rivalry against each other for winning over favors of the higher command. In this case, the Emperor/Emperess' favors. Nyack sort of believed that the Hari Order had less obligations than any other military groups under Vahana's command. So some time during the Prothean Reaper War, after Javik became an Imperial Guard, which made him in co-commanding the Hari Order, Nyack just had it enough.
Nyack knew that Javik was an Archknight Apprentice of the Empress, and to her, that was having "just way too much titles under a Prothean of his kind". She purposely provoked Javik into a duel "for honor's sake". And made a deal that if she won the duel, Javik would have to be executed because he'd be too weak to have disgraced the Fleet. The duel was approved by both Vahana and Teishen. During the duel, Javik managed to overpower her, which had actually amused her, and thus resolved their tensions.
The two then managed to work together afterwards, and found out they actually had similar visions in solving the favor rivalry between the two groups. They would ended up being together as bondmates.
Military Strength and Military Group Sheet for reference
Prior to Prothean Reaper War
During the Prothean Reaper War
Nyack is an OC by Essenceofvengeance, the RPer of Javik on Tumblr. Because he's done pretty well in RPing Javik, and he's a fan of my Prothean Reaper War comic, I decided to follow through his headcanon of Javik having a bondmate during the Prothean Cycle.
His headcanon told him that Protheans were an all-male race, which contradicted to my universe setting, so I asked him for consent in turning Nyack into a female. Yeah, here's what happened. :3