Well to say the truth I don't wana make him yoroichi level. He will get the demon slayer mark in the infinity castle arc and thanks for commenting it really helps.
I like your story , it pretty impressive he just gain a sword and basically win a training combat against a true warrior he is not yoriichi talent level but he is better than kokushiboo , How old is he ?
Will he get the slayer mark soon like yoriichi or will he gain it later like the other slayer ?
