As you might have noticed, if you perused the names above within Organisation XIII, each name has a common theme. You'll notice that each name has an X included, and this is to indicate that these characters are Nobodies who have lost their human form and their heart. However, they do retain some semblance of their former selves as these names are all anagrams of their human name. Take Axel, for example. Their former name was Lea, so scramble it a little and pop an 'X' in there, and Axel is born.