Nothing

In The West End, you meet Carina Billow, a woman who's mind has been destroyed by a powerful Vampire. Manipulated into eating rats to gain immortality. At first I thought it was just the Ascalon Club fucking with a mentally ill woman. But it's worse.

Carina is being mentally manipulated by a powerful vampire, forcing her to do awful things. She will actually beg you to kill her to put her out of her misery, and will thank you for your kindness if you kill her.

Earlier in the game when Jonathan asks Lady Ashbury about the bodies that have been found in the streets and about how someone seems to be following him (before we know its Mary), she seems anxious and has someone in mind. Most likely she fears Jacob Blackwood has been watching Jonathan, taking an interest.

Blackwood only speaks through Carina Billow once, mildy warning Jonathan off his "toy" but he does not seem to care enough about his little game to actually stop her being embraced. Evidence of his presence occurs when you visit the grave of Carina and find he has piled dead rats all over the poor woman's resting place - one last act of disrespect. I tend to think that doing this is both for his own amusement and a message to Jonathan that he has taken notice. Carina Billow's information when she is embraced suggests Blackwood maybe a member of Ascalon, it might have been interesting to meet him there.

And when you get to the very end of the game inside the Ashbury castle, one of the paintings on the wall was of Elisabeth Blackwood (Lady Ashbury) and Jacob Blackwood.

And when you read William Marshall's old tome before you reach the end of the game, you can see that Marshall holds Blackwood in contempt.

Jacob Blackwood is an interesting character and I wish they had given him more space in the story because it fleshes Elisabeth out a bit, gives her a backstory you can learn about as you get to know her and makes her a more rounded person with her own motivations. So when you get the first of the bad endings and she says "you have betrayed me", you get an idea of why she might react that way - rather than a lot of players being confused.

He definitely has the blood of hate. Blackwood was created after Elizabeth was bitten by Marshal and the two ranged across Europe killing for their own amusement. Even if he was created before Elizabeth has the blood of hate, it is highly likely he would have contracted it anyway. There is the possibly that he was always a bastard though. Perhaps not all the frenzied skals in the city came from Harriet Jones, maybe a few came from him returning to London.

There is so much potential in Jacob Blackwood in a hypothetical sequel. Jacob has the blood of hate, while Jonathan and Elisabeth are working for a cure. So much potential.

So a way to go about it is this.

If you chose the Embrace no one path, embrace some or embrace everyone.

If Jonathan and Elisabeth travel the world. They hear horror stories throughout Europe. Jonathan thinks it's some Ekon gone mad, but Elisabeth knows the truth. Jacob is back and the potential for another Disaster is strong. Their mission is to kill Jacob and find a cure for the blood of hate

If Jonathan and Elisabeth lock themselves in the castle. They spend years working on a cure and that's when Myrddin appears. He tells Jonathan about Jacob and Elisabeth is horrified. They know what they have to do. End the blood of hate

Jonathan embraces one too many people and Elisabeth dies in the "betrayal" ending. Jonathan locks himself away, that's when Myrddin appears. He warns Jonathan of Elisabeth's loose thread. He is causing atrocities across the land and is on the verge of creating a new Disaster. Jonathan will end the blood of hate once and for all for Elisabeth

Jonathan embraces everyone. Jonathan's bloodlust knows no bounds. Jonathan intends to build an empire on blood and there is one person standing in his way, Jacob Blackwood. It's an all out war between Reid and Blackwood and World War II is their battleground. Reid uses the Allies, while Blackwood uses the Nazis.

Ideally I would set the game during WWII with Jacob taking a position with the Nazis or Vichy France, and he uses the war to commit atrocities and spread the blood of hate like a plague.

I'd also have McCullum return. The Guard is reestablished, but it's clear that Reid and McCullum have to put aside their differences to stop Blackwood. Plus I'd just love the idea of Jonathan and McCullum basically saying "Look we have our differences as a Vampire and Hunter, but we draw the line at fucking Nazis"

As for how the Brotherhood of St Paul would return. If you let Swansea bled out/embraced him, then Usher Talltree would be your main ally from the brotherhood. But if you turned Swansea, Swansea would return and would be a very questionable ally.

aka I just want a game of Jonathan killing Nazis and Jacob Blackwood using Nazis to fulfill his goals but also embracing their ideals.