This was something I set up a long long time ago. If you look way back in CHP 15, you’ll see hints that this specific character might yet return one day.
I’ll be frank though… his role in the story, what he was supposed to stand for (a Foot ninja looking like every other one, but with his own story, objectives, personality, etc) have been all taken by Sadao already. :\
Anyways, he’s got a new purpose now.