Arden Lyn was a master of the unarmed combat discipline Teräs Käsi in the game Star Wars: Masters of Teräs Käsi.
Lyn belonged to the Followers of Palawa who, according to their entry on Wookiepedia, “developed the martial art of Teräs Käsi as a means to keep the Jedi in check, presumably so that another world would not be destroyed by the Jedi Council. They also mastered a deep trance technique which they could use to sleep for decades without aging, somehow tapping into the Force through meditation.”
She later joined the Legions of Lettow and became romantically involved with their leader Xendor. Much later on (see Lyn’s entire story on her Wookieepedia page) Arden Lyn had dealings with Darth Sideous.
Edie Mirman voiced Lyn in Star Wars: Masters of Teräs Käsi.
Qi’ra was revealed to be a master of Teräs Käsi in the film Solo: A Star Wars Story.
Here’s a peek at Arden Lyn in Star Wars: Masters of Teräs Käsi.