Normally youre only supposed to carry over your completed map from a Jonathan cleared game to a Jonathan new game +. With this glitch you can start a new Sisters, Richter, or Old axe armor game with your fully completed Jonathan map. Heres how:

1. Click on the new game + bat icon to the right of your cleared Jonathan file.

2. On the 'normal' or 'hard' difficulty screen, press B to cancel and go back.

3. Go to any blank file and start any new game be it Sisters, axe armor, etc.

4. Voila! Fully completed map!

This makes exploring in Sisters, Ricther, and Axe armor mode a whole lot easier.