Miyamoto Musashi taught Kahn about Space Law and how a Samurai fights.
However, his temperament and goal were different than Omega's.
Because, unlike Kahn, Omega had no intention of becoming a Hero of the masses or wanted to save the world as his responsibility for any reason.
Omega did not even care if he died tomorrow. But what he cared most was the one thing that made Miyamoto Musashi accept him wholeheartedly as his Successor…
His loyalty and devotion to serve his master. In essence… Omega had the true spirit of a Samurai.
And as his training in Niten Ichi-ryū progressed, Miyamoto Musashi realized that Omega was a better-suited candidate to impart his wisdom and philosophy in warfare and the code of the warrior, even better than Kahn.
To him, Omega was like a prophesied genius that he had been waiting for centuries and finally found him while Musashi was reluctantly forced to train that genius.