The HxD part was annoying but not that hard, I managed to unlock all mentor costumes with thisI actually looked up on a few tutorials and read the whole thread again, i actually got to convert my save into a PC save and modify it with the save editor and then transform it back to switch. The part of Hex editing was hard but not so troublesome(since its very few things to do).
I got everything i wanted this way, just the new mentor super souls arent unlockable with the save editor i believe, since they havent appeared there for me. Problem is i wanted some of those super souls XD.