any save file with the same main character will suffer the 4th wall break. However, if you're zealous enough, you can make a new character (preferably a different name as to not confuse yourself) and repeat all of the quests until you meet the nameless.
Although, it's possible to make separate characters for each options, I suggest you don't overwork yourself just for this.
I have two main characters right now, I'm thinking of making a 3rd one because I picked to fight against the nameless for both saves.