Man, I forgot to include that thing that I had in mind for a long time in my post! That was so silly! Maybe, I'll try to include that on my next, if chance will permit me.
Yeah sorry 'bout that, I think I should get some more sleep, my mind isn't functioning very well... Uh no... on second thought I'll just eat some noodles.
So Onyx doesn't have anything to do with Mitsu and her clan except he just thought Mitsu how to do magic? And I thought Onyx and Mitsu have runes on their body, if I'm not mistaken. So that thing made me think that they are quite connected and also they had traveled for some time too.