Khyin Ialentus
Khyin Ialentus was once a promising Trill Starfleet cybernetics expert, that is before he was joined with the Ialentus symbiont. Perhaps because of his innocent personality, telepathic status or something else entirely, Khyin's joining went terribly wrong which resulted in the personalities of the symbiont and Khyin himself, not meshing quite the way they should. A series of events related to these complications resulted in Khyin engaging in 'Reassociation' with partner of Ialentus' last host. He has since been expelled from Trill society.
Now the innocent and well meaning personality of Khyin and the tortured, ancient mind of Ialentus occupy the same body. While their personalities have coalesced somewhat normally post joining, there are still some oddities that have prevented Khiy from returning to any semblance of normal. He has since resigned as a Starfleet Officer, though continues to work as a civilian on side projects, most notably his own research into immortality and life-extension. His brilliance has multiplied but so has his seeming eccentricity. Most find him happy, sensitive and kind, having the personality of a more mellow puppy. While some find his odd use and arbitrary exchange of pronouns off-putting, most are keen to overlook it.