User blog comment:WarfareOverseers/The Dishonored Theory Page/@comment-1185827-20170926094415

The Outsider says "Delilah is a part of me now, and I don't like it."

Theory: Delilah has not simply drawn from the same power source as The Outsider, she is 'poessessing' him, in the same way Grim Alex possessed Hypatia. This is why Delilah is able to revoke Corvo's brand, because she is somehow the same entity who bestowed it. It's also why Delilah is able to draw the protagonist into The Void for a chat, the same way The Outsider does.