It's got to be tough to write a series set almost 1000 years before all the others at a comic book shared universe, if only because it limits just how much you can get away with in terms of huge, world-shattering events. That's a careful path that Robert Venditti and Bernard Chang try to walk in "Demon Knights" #19, as they need to find a way to make their vampire horde dangerous even while having to recognize that readers already know the world doesn't get wiped out by them.
Venditti has latched onto the one thing that writers can get away with in a situation like this: don't worry about the big picture but rather the small details. The vampires might not destroy the planet, but the existing cast of characters is another story entirely. With one of the members willingly falling to the vampires, Venditti keeps the stakes high (no pun intended) for "Demon Knights" #19.
That said, the logic feels a little odd on why the one character ends up deliberately stepping to their undeath, even as Venditti tries to work with what was already set up some time ago. It's an interesting route in terms of what people believe about predestination, though, and I feel like Venditti has a lot of potential in his hands for where the story moves from here. That's good, because the battle itself is a little lackluster in places; vampires versus Amazons should be gripping, but once again it's the big details that seem almost brushed to one side in favor of the smaller drama.
Chang's art is, as always, excellent. With sharp ink lines that sculpt faces onto the page, each character has a distinct and unique look. The first three pages are a great example of how good Chang is with facial expressions, too; just look at Vandal Savage's face from one panel to the next. It's always very obviously him, but he changes the features subtly to match Venditti's script and the words coming out of Savage's mouth. Chang's good with large crowd scenes, too; your eyes go to right where they should be, even as there's lots of detail to examine should you choose to do so.
There are fun little moments in "Demon Knights" #19 (I like the idea of why even Lucifer is extremely worried about the vampires winning), and on the whole the series is chugging along nicely. I'm hoping for the next storyline to have a bit more punch to it, though; "Demon Knights" is so isolated that it's going to need something big to keep people's attention. All in all, though, a nice first storyline for Venditti and Chang working together.