Firestorm is a merge between Millenium, EarthQuake, Pandashan and Ashran. We've decided to merge all our servers into one: Firestorm.
To play on Firestorm, you need to merge all your accounts into a Firestorm account at https://firestorm-servers.com/merge/index
The merge of all our servers means that we're now using one unique account for all your old accounts.
You can reset your credentials here (even for your old accounts):
You can contact an administrator on the forums with many informations regarding your account (character names, creation date, specific details about your account etc) and then you'll be able to reset it here https://firestorm-servers.com/welcome/legacy_forgotten
If you didn't link your account but it says that it is already linked, this is because a third party have your username and password. We cannot determine the initial owner of the account since you're responsible for the satefy of your own account.