I am using the credentials of my battle.net account which cannot be unlinked, thankfully. That's why I am insisting on steam from being unlinked cause once that happens I have to log in from where I bought the game if I had bought the game on steam I couldn't have unlinked steam but since I bought the game on battle.net that can't be unlinked and steam can... He probably linked his steam during the transfer. When I was offline for like 2, 3 months. When I came back my battle.net credentials where changed so I had to change them back. For battle.net is easy cause I have everything in there restore codes and master cards etc. But now my Bungie is linked to a steam I cannot access or have and I can see the guy is playing with it.

Okay - usually we can still see the BNet account linked, but I'm guessing you have it hidden. The issue lies with the fact that all authorizations are completed via your platform authorizations service. Adding/removing accounts to the Bungie profile is done via the platform authority (Steam, XBL, PSN, etc), and it is threaded throughout various systems. Therefore, without authority, the account cannot be removed. As you noted, the user probably hijacked your BNet account in order to gain access to the Bungie profile. This means you didn't have MFA/2FA setup with BNet, otherwise they would have prompted for a confirmation if someone used your credentials from an unfamiliar location or IP. That's in the past however, so there's not much you can do with it now. You need authorization via the steam service to remove it, and that means either Steam has to forward their account permissions to you so you can withdraw the parasite account (not likely to happen) or they will close said account as a violation of their ToU. This stops the account owner from playing, but unfortunately, also makes it impossible to remove the account again, since now nobody has access to it. The latter option, if implemented by Steam, would at least stop the person from using your D2. They also have joined a Clan using this account. Is this your clan? or a foreign clan? If it is your clan, you may want to talk to the admin and have them removed. [b]Have you tried making a new Bungie profile[/b] and linking your BNet account to it? If it works, it should allow you to run the transfer process again and link it to the proper Steam account. *** [i]At the very least, I would make sure to change the password on BNet, Steam, [u]and any linked email accounts[/u] - as well as activate 2FA/MFA on everything - BEFORE trying to fix anything further. That will keep them from being able to re-access and alter any changes you try to enforce [/i]***