On CM there was a COG account which was linked with your Archlord account.
On WZ there is a Webzen account to link with your game account.
The COG account and its attached personal info is NOT being transferred to Webzen accounts in the upcoming account transfer.
You must create a NEW WEBZEN account for each and every Codemasters account you are going to transfer.
You create that WZ account, using whatever information you like or must, but does not have to resemble in any way the COG account currently attached. Webzen accounts are very easy to make compared to COG accounts.
When the transfer is happening, you then open that WZ account and you will be given the opportunity to enter the Transition Code currently found in the COG account.
Enter it.
That will then enable the transfer of the Game account information (Chars/Levels/names/invent/and so on) from the CM account to the new Webzen Account.
You do not have to use the same email address if you don't want to.
If you have used an email address you used with CM, to open another account with WZ at the moment in the Tullen Server, I think you can still use that email as the account info will just be added as additional servers you have on that account. We will see.
Otherwise, you cannot use the same email to open multiple accounts on WZ, just like it was with CM.