These are the humans under the oppression of their vampire overlords. They're used as sacrifice fodder as well as for their other abilities, but they won't sit quietly and watch it happen. There's about to be an uprising.
Bloodsoaked Champion is the humans' go-to hero. This war veteran charges against the vampires and not even death will stop him. He's a good early threat, but my favorite part is the ability to continue bringing him back to sacrifice again.
Doomed Traveler This poor guy wandered into the wrong town. He was just passing by, but the courts don't distinguish him from their captives and won't hesitate to sacrifice him, too. But his spirit lingers, leaving behind a 1/1 Spirit token. Two creatures for 1 is great in my book.
Liliana, Heretical Healer
was just a victim like like others until she couldn't take it anymore. She was forced to watch one too many deaths and turned to necromancy. At first glance, I didn't realize how useful she could be to this deck. She can continue to bring back Doomed Traveler or other humans for sacrifice fodder or can be useful in returning discarded vampires. I've used her to bring in Falkenrath Aristocrat when I lacked the red mana needed to play her.
Zulaport Cutthroat is not exactly an ally to the humans. While being a human himself and knowing he could become a tribute at any time, he still exploits the situation for his own gain. And ours. Having another Blood Artist effect is great especially when it still triggers when the opponent has hexproof.
Gather the Townsfolk At this point, the humans are meeting in secret. The oppression has gone on for too long, so they plan to revolt, putting some human tokens on the field...that ironically just get sacrificed.
Lingering Souls Like the spirit of Doomed Traveler, these are the souls of those fallen victim to the vampires. Flyers and bodies (well...) to sac, and you can cast it all over again. Where's the downside?
Ghost Quarter is the abandoned section of town that has been cleared by the three courts. Perhaps it is where the Lingering Souls come from. It's great to get rid of nonbasic lasids, but I also like it for color fixing even at the sacrifice of one of your own lands.
Westvale Abbey
is a place where the humans conduct their final plan for revenge...but at what cost? Seriously, though, putting humans out is awesome by itself, but sacrifice to flip it while Dictate of Erebos is out, and it will clear your opponent's board if not cripple it. Then you've got a demon to beat the hell out of them with.
Fatal Push would go really well with the revolting humans theme, but I opted for Tragic Slip because 1) budget and 2) the -13/-13 would kill indestructibles. It just feels like it's not as limited.
I also went with Dictate of Erebos over Grave Pact for budget reasons.