Dr. Seward's comment about Vanessa manifesting three distinct personalities confused me so I re-watched the scene. She is listening to the recording made during the Blade of Grass episode. IMO, the three personalities that Dr. Seward hears are Vanessa, Lucifer, and Dracula, but of course all of them are in Vanessa's voice because Vanessa is verbally reliving what happened to her. She had already mentioned seeing the Orderly as a distinct, normal, separate person so Dr. Seward would have considered him to be a legit memory, and not a 4th personality.

I think this scene was included as a callback to the ending of the episode, in which Vanessa defeated Dracula and Satan by allowing herself to unleash Amunet. That links to her saying that she 'accepts herself' in this episode whens she allows Dracula to bite her. I think that Vanessa is embracing her dark side to defeat Dracula, not to join him.

I was pleased to see The Creature/John Clare reunite with his family. As soon as his wife told their son that they would be happy for ever and ever, I just sighed. The minute anyone says that sort of thing in a story like this, you know they're doomed. OTOH, if the show isn't picked up for a 4th season, at least this one lost soul may have found his way back to the light, and that would be fine with me. (Of course, there are still the two hour finale left, so there's still plenty of time for tragedy to strike them again.)