@RektSmurf Unless you are still using Opera Presto (Opera 12 and older), want.dat isn't useful. Regarding Login Data, the file that stores your saved passwords in Opera Chromium, those passwords are stored using your OS login credentials to encrypted. That way, your saved passwords can't be used in a different computer or by a different user in the same computer.
The only way to transfer your passwords to a different computer or OS installation is by using sync or by exporting and them reimporting them.