Monster Hunter Portable 3rd HD

[LunaMoo]

"Synchronize save" can be used to save any character over any existing save, for example you could make a savestate on each of your characters you wish to save, then create a new game save(better backup old save before;p) load a savestate and with this cheat you will be able to save characters from the savestate to a new save or mix characters from different saves.

"Delete save/save only current char" sets a flag telling the game that save is corrupted which allows you to save your current character to a new save, but your other characters are deleted during this, to be safe you should backup your save before using this cheat.

Generally both of those patches were made to fix the "cannot save in-game" problem which lots of people who abuse savestates had and not to swap/remove characters, but yeah they can be used that way. You could always just create a new character and save it over one you don't want, having an empty slot or a starting character doesn't really make a difference for other characters.