It makes sense to a casual viewer of DC media, like me, that Ras would take over the mantle or at the very least fight against the vampiric forces one way or another. He wants a better world, one more at balance with nature. At least from what I've seen. And I don't think the vamps have much concern for the planet, considering I think they blocked out the sun (not great for almost every living thing lol) and he would at the very least fight them through subversion and low visibility/high value target assassinations with all the trained killers and black ops style knowledge at his disposal. These are my thoughts at least, I could be very wrong lol. Please agree or disagree so I know. This is my first time seriously posting here.