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.
All the books are chock full of these and it would take fifty pages or more to list them out. Combined with the violence and horror of some scenes, it's easy to accuse the series of Mood Whiplash, but the scary scenes and the funny scenes are spaced out enough for the reader to better acclimate to the change in mood.
From Shalador's Lady: "You think you can give me sex that's as good as these cookies?"
"Jaenelle says it is like deboning chicken. Just hook two fingers around the spine and pull."
Tear Jerker: there are some truly heartwrenching moments throughout the series, including but not limited to Jaenelle's rape, Daemon's slide into the Twisted Kingdom, the massacre of the unicorns, and Jaenelle's supposed death.
Most recently in The Shadow Queen, there's Saetan's own (temporary) fall into the Twisted Kingdom and his explanation to his son Daemon about what caused it. "It could have been you."
From the short story about Zuulaman in Dreams Made Flesh: What happens to Saetan's third son. "Look, Andulvar. Look what they did to my baby. Look."