Geron was joined with the Fryll symbiont at the age of 19 after passing extensive training and testing, approved to be joined. Geron was a studying to become a cultural anthropologist when he was joined and the added experience of the symbiont was enough to allowed him to granted a doctorate in the subject. Fyll has had many lifetimes a good portion of those in Starfleet. However, he did not want this lifetime to be the same and chose Geron because of his academic life and skills.
Geron still at times has a little bit of trouble with memories from other lifetimes becoming overwhelming. The joined pair were introduced to Solas Tempus as an instructor in the training process to becoming temporal operatives. They both found the work intriguing and actually got to witness a temporal operation first hand. Soon after, they joined up and quickly became certified as temporal operatives.
His specialty in cultural anthropology is in cross-race relations of early space travel. This includes the early 22nd century Earth and its interaction with Vulcan, Andor, and the Klingon Empire.
In his personality profile before joining it is noted that he is a thinker and tends toward inaction in favor of considering his options and that this could be a liability in some situations. After being joined, the symbiont has tempered that instinct toward inaction and consideration somewhat but it still may be a liability. He is a dreamer and idealist, this doesn't always mesh with memories from past lives and causes emotional conflict sometimes, especially during military operations where Geron's instinct toward not fighting is at odds with military training that Fyll brings into his mind.
Geron Fryll is currently assigned as a temporal operative to the USS Shadow River.