Alright, thanks for following that up with him.
Username changes happen in a prescribed time period a few times per year. A thread is posted in the Meta area a few days in advance as a warning, and a three or four-day window is made where you can change your username via your account settings. The most recent one is linked here:
https://pokemondb.net/pokebase/meta/66987/
Unfortunately you'll probably have to wait a while longer to get a username change done.
The usernames that appear to use a different font simply use Unicode characters and symbols as opposed to a standard keyboard alphabet. You can find these symbols online -- some generators for them exist as well. This next stuff might go over your head, but Unicode repositories exist here which you might find useful.
http://cldr.unicode.org/
