Remnants/YMMV

The Chris Carter Effect: Um, why do they have super powers? Who or what is the Ancient Enemy? What are they even the enemy of? And hell, what the heck happened to D-Caf?
Hilarious in Hindsight: The books begin in approximately 2011. There are computer-controlled cars that drive themselves with on-board voice operated internet access, and the "link" device which hooks over the ears, acts as a cell phone, video camera, has internet access, and is voice operated. Considering some of the technology today, neither of these advances sounds entirely out of place.
Nightmare Fuel: Arguably the whole point of the series. Listing it would be tantamount to listing the details of the story, just read the plot summary above and bear in mind that that summary left out most of the most horrifying parts. Hell, the main character even watches as the Earth is destroyed. In extravagant detail.
- Look up Heironymous Bosch. A series of his paintings are the only security system necessary for the Tower, and they're chased by nearly every Body Horror and Hybrid Monster in the paintings. Not to mention the unmasked Reapers, or Tamara's Baby, which is Nightmare Fuel long before the readers find out just what it is.
The Woobie: Billy Weir.
- For that matter, Mother (in a Woobie, Destroyer of Worlds sort of way), once you find out that she's sapient and went insane from enduring hundreds of years of isolation.