These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Markoff, Stevens and Krax. They all do some pretty cruel things throughout the course of the novel, but Markoff and Stevens definitely reach the Moral Event Horizon in the novel's epilogue when they force Michael Altman to fight off their new Necromorph type (which happens to have been partially created from Krax after Markoff decided he was "expendable") with a spoon, while they watch from above drinking champagne and grinning to each other.