You lack power for a certain creature and what better option than August (Fairy Tail) to be able to counteract the magical part more efficiently; and then you could go to said world to search for the God-Slaying grimoires
I wish you could have Sasaki Kojiro (Record Ragnarok) as a template to specialize in the oriental sword since he also has his Skills and above all Hrist (Volund/Re:Volund)