The NightMare account was registered by someone in a different country to you and does have some (minimal) stats on record. I will make a one-time exception and recover the name for you as the account appears to be dormant, but please confirm you understand not to get into this situation in future. Remember, it can take a matter of seconds for a name to get re-used by someone else if you use /changename. Ideally this isn't something admins would get involved in.