The Vanguard cross the Moral Event Horizon at light speed and never looks back, with Giganta Asuka and Black Mari wiping out entire city-blockfuls of people and gloating about it, not to mention killing Super Rei (by ripping her heart out) and Kiki (a little girl, by squashing her like an over-ripe tomato) and going all "I just did that, and what are you gonna do about it?" to their onlooking friends.
Extra-TERROR-Estrial Thrills and Chills:
The monsters of this tale are freaking Xenomorphs. An unknown amount, but topping at a possible several thousand, courtesy of the hive being the remains of the USCSS Covenant. The moment that Vasquez figures this out, her reaction is a highly understandable "Oh, Crap!"
The second chapter gives her a good reason to be (a bit more) afraid again: This version of the Covenant ran into the home planet of the aliens that created (the alien half of) Sil. The one from Species. The result are super-Xenos that are harder to kill thanks to Sil's Healing Factor and can sprout Combat Tentacles at the drop of a hat. And David's got direct control over them.