I was thinking just now about all of Marvel's characters who practice martial arts and it just occurred to me that Karnak may be the very first martial artist who was "themed" after the the traditional/sterotipycal practice. Karnak predates both Shang-Chi and Iron Fist so by default Elektra, Collen Wing, and White Tiger all appear after him. Only other character who I can think of that may have him beat to this title is Daredevil but he is of course themed after a devil and when he first appeared he was more of a boxer and acrobat than a martial artist if I remember the history correctly. It wasn't until much later that Daredevil was even claimed to be a ninja of sorts.
Anyway....does anyone know of a character who is a martial arts themed character that predates Karnak?
Karnak 1st apperance Fantastic Four #45 (Dec 1965)