Usually FlyOrDie and its moderators do not endorse people using multiple nicks or continuously changing the nick you already have which is why the solution to this is so hard to find. :|
paid for the extra features of the game FlyOrDie does allowed
Here’s the direct Quote from
How can I change my subscribed nickname?
Send a message to FlyOrDie Support containing your invoice No. (or order ID, account ID). Please also include your original nickname and the new one.
A nickname can be changed only once. The change is irreversible.
NOTE: If your nickname contains special characters, please include a link to your player's info page, or use unicode UTF-8 encoding in the email.
*Make a smart choice, it took me a while to find this link, and please don’t add letters that identify you as part of a group or team that you are not actually a part of ( UAG USA Unido )