Each profile is able to create up to 5 characters. Since the game is 2 players splitscreen and 4 if you activate the experimental mode you will be able to create one character for each controller in your profile. Each character is unique and this tool will also allow you to edit your character.
Right now you have access to any item that are in the game but later you will be able to custom your character depending of the item you have found in the game.
The tool will be a modified version of the subscriber one so you guys will be able to edit at anytime your character.