[member="Kian Karr"] has the right of it.
Reborn and Shadowtroopers were people who were infused with the force. In the Shadowtroopers' case they were infused with the force through plot-crystals that granted them access to the force. Not a great connection, but it was there.
Kyle Katarn found out about it on Kejim, a small mining colony and from there his reemergence as the BEST JEDI EVER began. Valley of the Jedi, some training at the jedi academy on Yavin and they were set.
Yep, I love Dark Forces 2, Jedi Outcast and Jedi Academy.