User blog comment:Subject 16*/Assassin's Creed: Revelations - News/@comment-3349505-20110509223540/@comment-4369008-20110510173206

Shaun's eager to go into the Animus because he's convinced himself that he has an ancestor that is all awesome and stuff, hence why he mentions the 'Norse ancestor'. That's just hopeful assumption he has of his past.

But seeing as it is the Animus, it wouldn't be unreasonable to believe that 'an Abstergo employee that had previously connected to the Animus' could transfer the characters over. Maybe as we progress through Abstergo as an employee, we could 'learn' ways to control the Animus and add the Brotherhood characters in, or maybe have a sync system with Brotherhood through Uplay (or spend Uplay points to unlock the 'Brotherhood Persona Pack').