[quote=@Trivval]As you can see the dialog is written in German and Cyrillic Russian. My initial idea was that any scene involving the two of them would  have the dialog written like this, whereas when they are by themselves or with their own people it would be written in English. Your opinion on this would be greatly appreciated.

Sorry if this is the wrong forum as well... I'm not really looking to collab write the story, just to provide background and help me develop it.[/quote]
This is probably the very "correct" forum to put this.

It seems to me the plot of this story is at its foundation a story of survival as is any war story. In this case you have a race of super human vampires who have a slight advantage over the mortals, depending on what your rules of Vampires are. I've seen several different examples. I actually like the rules laid out by Stephenie Meyer in her Twilight Saga. But if you have your own ideas, you should have them written out as a reference for yourself or for others if you turn this into an RP.

As long as World War II continues, the Vampires at the heart of Leningrad will have fresh corpses to feed off and their behavior will be concealed by the events surrounding them on a grand scale. But once the war ends, then the story would become trickier. They would then be forced to conceal their identities in other ways; possibly moving to other countries simply to avoid being recognized by someone who may have known them in a past life. But as a Vampire, they would have to move every 15 or 20 years anyway simply because their bodies won't change while the mortals around them will.

I assume your story will focus on the Vampires in the city during WWII and not on what happens to them after the war. They should have an advantage of immortality. What about rapid regeneration from wounds? Is that a Vampire strength or will they succumb to the damage of gunfire like a mortal? Those questions should be addressed before coming up with a plot.

Assuming the Vampires can regenerate, they will be tough to kill. Your story can focus on a firefight with German Vampires fighting against German and Russian mortals. The Vampires will eventually run out of ammunition unless they are looting it off the mortal corpses as well as their blood.

If your story is focusing on the mortals, then you have the plot device of placing two former antagonists along a unified front facing off against a common threat. This story will focus on the survival of the mortals trying to overcome the German vampires' strengths.

There are several other subplots you can generate from this theme as well.
1. Who is in charge? a Russian or German
2. how to get the corpses out of the killing zone without providing additional targets to the vampires?
3. Romance
4. Betrayal. maybe a Vampire makes a deal with a Russian or a German to give up his people in order to survive. But Betrayal can go both ways.

I hope this helps. If not, ask questions. We can discuss this.