Kaino has been active in the Hammerfell region as a mercenary, so there's a possibility that your character could have either heard of him or posted a job offering in a tavern he frequents, in case there's work to be done.
More than just a mercenary, Kaino specializes in anything Daedric. He will find and deal with vampires, werewolves, ghosts, those possessed by Daedra, and any kind of "evil spirit". He doesn't hate them all, though, and could work with one monster if it means catching another.
As mentioned in the previous point, Kaino isn't shy to mingle with Daedric creatures to further his own goals. Perhaps you've got a vampire that he's been hired to hunt down yet the guy who hired him is an asshole, so Kaino ends up siding with your vampire instead? Perhaps you've got a Daedra that he summoned to extract some information from, and they get caught up in the events? Or maybe he killed your character's werewolf cousin and now Kaino himself ended up being prey? The possibilities are endless. Bottom line is: I love dark stuff, Daedric lore and monsters, even though I play a human myself.
While Kaino is half-Imperial, he still feels drawn to his fellow Redguards. He's a free agent, not particularly identifying with either Crowns of Forebears, nor is he religious, but anything that happens in the desert is almost a certain match. Caught in the midst of a desert storm? Getting together with the Ash'abah to clear a village from Ra-Netu? Or perhaps you've got a proper, grassroots Redguard that would like to lecture Kaino on his disregard for religious taboos? Bring it on!
These are just a few examples of what we can get into. I'm always open to suggestions, and do feel free to nudge me on Discord: enemy#1837 or in game: @envoii