From Star Trek: Theurgy Wiki
Before his death, Ensign Lin Kae was a Holographic Specialist on the USS Theurgy in 2381. Before he was killed on the Versant, Kae aided in the opposition against the parasites that compromised Starfleet Command in the end of the 24th century.
Kae was born to a Bajoran ambassador and a Starfleet lieutenant working aboard Starbase 237. As a child, Kae suffered from extreme immunodeficiency, forcing him to live the early part of his life within a sterile environment. His father, an engineer aboard the station, configured the safe room with holo-emmiters and programmed various programs to aid with kae's schooling and social interactions. By the age of eight, Kae had learned to reprogram, using it to advance his education with more challenging tutoring and reconfiguring the teacher hologram to provide an even more adequate teaching experience.
By the age of fourteen, Kae's immunities had grown strong enough to let him integrate into society, though he still chose to spend the majority of his time in holodecks. By this time, he had reached the educational level of a student three years his senior, and chose to apply to Starfleet Academy and it's engineering program. His major was in Holographics, though he proved well versed in a number of fields, taking special interest in projects that were still in early development. After graduating, he returned to Starbase 237, where he served under his father, learning much of his trade from him.
When the call of a starship finally reached him at age nineteen, Kae requested a transfer to a Sovereign class starship, where he worked on warp cores for the first time in his career. While there, he altered the Emergency Medical Hologram on-board to match specifications more closely resembling the Voyager model, allowing it more adaptability and longer lifespan without the program degrading. When the program began to seek growth as a person, another engineer reset the EMH to it's standard format.
Having spent his life with holograms, Kae was more sympathetic to them, and the reset of the EMH's program resulted in him taking a transfer to the Jupiter Station Holoprogramming Center, where he continued research in the field. While refinement of the Emergency medical Hologram was the main work put forth there, Kae took an interest in the development of Isomorphic Projections, seen as the evolution of Holographics. Information about the projections were brought back from the Delta Quadrant, where it was used by both a species known as the Serosians and a group known as the Think Tank.
Kae would make his final transfer to the Theurgy after hearing about its ship's AI known as Thea. Supposed the most advanced hologram devised yet, Kae wished to observe it himself, and to work on developing it further using the knowledge and training he had obtained over the years. He joined the crew a month before the trouble began, but was unable to interact with the ship's AI beforehand. As such, his interests had to be shelved for a later time.
The most obvious feature about Kae is his Holo-Addiction. To say he struggles with it would be incorrect, as he has fully embraced the disorder. He oftentimes appears more capable of befriending holograms then flesh-and-blood people, having spent more then half his life in the company of holodeck characters. This attachment makes him an advocate of Holographic rights, which came into question after the illegal release of a Holonovel “Photons Be Free” which told the story of Hologram oppression by the Federation. As a person, he is often easy going, though is less confident around flesh-and-blood people.
He describes himself as an agnostic, having been raised in his mother's religion through holographic ceremonies, but in his adult years, he chooses to forgo wearing his Bajoran earring and not observe any religious traditions on either the Human or Bajoran side. He is still tolerant of religions, however, as he participates in any sort of functions, be they from his own race or any other, if he has been invited to take part.
Kae looks young for his age, likely a result of years spent living in safe rooms that have kept him from the wear and tear of the real world. His biology is closer to that of a Bajoran, featuring a heart that is mirrored on the horizontal axis as opposed to the human vertical. This results in any puncture to the lower ventricle to be a instantly fatal one. Save for this difference in hearts, the only thing differing him from human is the ridges on his nose, from his mother's side. Outside the Holodeck, he doesn't often wear anything other then his uniform, even when off duty. While inside the Holodeck, he will often wear period clothing to whatever simulation he is running. To save on energy credits, however, he programs the Holodeck to simply overlay the clothes on top of his physical template, as opposed to actually replicating them.