In fact, you cannot fully customize the character name. All names are preset to correspond to a certain ID, meaning there is a built-in list of names from which you can choose one, but you cannot customize it.
you can find an all character clear save and use the tool to export the characters, then re-start the game, save it and import the characters data, and modify the level as you want.
Can anyone tell me how to change the Battalion with the V3 Save Editor?, after I changed it and restored it with Edison, the character who equiped the changed Battalion just show blank(but occupy a seat in the Barracks)