Brium Tallistor
Ok back, sort of.
Anyway, I have a few characters that could interact with him.
Rocho
a trained force sensitive trandoshan hunter/mercenary. He especially excels at two things, physical enhancement and force sense (especially in regards to recognizing people through the force). He's a follower of the Scorekeeper to an extent and that is what guides his actions. If a job isn't a challenge, it's not worth it unless it pays well enough to let him do an actual challenge later. He gets along well with most and works in teams pretty regularly. Honestly, while he is a bounty hunter, he works as a mercenary rather regularly. He's one of my more dangerous fighters. He is rather likely to notice that Katarn is force sensitive.
Mariah of House Marr
One of my few non-force sensitives (I have three total). And also one of my only characters who is not the greatest fighter. While she's a good marksman and is fairly fast, she's small, and not particularly strong. For this reason, when needed, she uses droids. One of whom she can gain complete control of, allowing her to use them in her place. She's a mechanic (ship, droid, cybernetics, all sorts of stuff), an entertainer, a smuggler. Basically she does what pays. She doesn't do bounty hunter or mercenary work much though. Too much danger, not enough pay-off. Also...she just isn't really that violent of a person. She's a lot older than she looks (and the way she acts goes either way) but she's very much otherwise just a human with a crap load of skills. She might not recognize Katarn's force sensitivity, but if she found out she had it, she knows stuff about the force due to her parents. She can't teach him anything about lightsaber combat really though.
Ardon
Another non force sensitive. He's mostly a smuggler and ship captain for Tillian Family enterprises. He's also got a speech problem, needing cybernetics to actually communicate. Unfortunately they were of inferior design, and that resulted in him speaking somewhat like a droid. He's a pretty moral person, somewhat better than Mariah, but much better than Rocho. He's slightly force sensitive, but not a whole lot.
Kovhorn
A mandalorian and non force sensitive. The man is pretty much a walking tank, he covered himself in some pretty hefty armor after he nearly died fighting a dragon. I noticed your guy has a fear of mandalorians, this could be a way to have fun with that. He does bounty hunting but he's even more of a mercenary than Rocho is. Kovhorn hates sith, but otherwise doesn't care so much about other force sensitives or their orders. He's not for or against them. He would absolutely not be happy about Brium using mando armor while not being one, but if the fight was fair,
may respect that he won. Kovhorn is a lot more cold of a person than the other three. While he doesn't kill based on the challenge of the target like Rocho does, he's not as friendly as the Trandoshan.
Shavara
So you got two options here. Shavara the priestess scientist, or Sar Vun the rebel. Shavara publicly is called a Vo Ni (kind of compare them to priests or priestesses in regards to how people view them, it is a long culture that's hard to explain on here). Normally her jobs involve exploration and research, sometimes involving alchemy. However she doesn't have a huge reputation, and is just another one of the Vo Ni, who is young. As Sar Vun however she rebels against the Eternal Empire, aiding the Eclipse rebellion wherever she can. Sar Vun probably has a bounty on them. Nobody can really say whether the person calling themselves Sar Vun really is the original or not (someone in the history of her planet) becuase the shape, size, and even gender change. And the alchemic skill of Sar Vun was known to allow him abilities that exceeded normality. Truth is she simply is capable of shapeshifting, and wears a mask that hides her true presence in the force, replacing it with its own. She's kind enough that even if he did lose a fight with her, she'd probably avoid killing him. She doesn't really want to fight and only does it for the sake of her people.