Hi there.There's a few different things you're talking about, so I'll try to address them separately. If the account your characters were created on is your brother's Xbox account, he can use Xbox's Game Sharing service to share his DLCs with your own account. [url=https://support.xbox.com/en-US/help/hardware-network/console/my-home-xbox]See Xbox Support to learn about this service[/url]. However, the characters are tied to that account and there is no way to transfer, merge, or access them from a different Xbox account. You would have to create and play with different characters on your own account. To switch Xbox accounts and continue to use the same Steam account via Cross Save, you would have to disable Cross Save before you could unlink your brother's Xbox account. That will incur a mandatory 90-day cooldown before you can use Cross Save again with your own Xbox account.