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.
YMMV: Deltora Quest
Anvilicious - GAMBLING AND DISHONEST MONEYLENDING ARE VERY VERY BAD, we get it already, please put down the hammer Miz Rodda ma'am....
The Granous, who force their victims to play sadistic games and bite their fingers off.
For added fun, those flesh-eating plants? They're partners with blood-drinking ones. And they're grouped together on the same island. So if by some luck that you're shipwrecked on that island? Watch where you're going and hope you have adequate protection. Even funnier? The author is Australian.
The Sister of the South. ESPECIALLY the guardian. Ugh...
The Grey Guards, whose poisonous projectiles cause agonizing deaths.
The Glus. Especially in the anime.
Thaegan has some moments in the anime. Most of the time she is enjoyably over the top or funny as hell. However, when she decides to get serious she can be terrifying especially when she's laughing psychotically.
Something like 85% of Isle of the Dead seems like it should also qualify - the book, from hitting the Lighthouse right on to escaping from the Lady Luck inspires a creeping horror. The crew.... And then there's what happened to Doran.
The Woobie - Oh hey, Jasmine! Let's talk about your life. You grew up in a forest. When you were seven years old, your parents were taken away, presumably to be killed, and your home got burned down. You had to fend for yourself. When you were sixteen, two strangers invade the lifestyle that you made for yourself, and your dead mother's spirit made you leave your home to go on a quest with them. You had lots of trouble because you could barely read or write, and most people thought that you were mad. Then it turned out that the guy you kind of liked was a servant of the Shadowlord, and not even human! Eventually you discovered that your father is not really dead but all that he has been through has made him a completely different person. And then it turns out that the other guy you kind of liked was the heir to the throne and became King. Later, you found out that you had a sister, Faith, in the Shadowlands. Another guy you kind of like dies on the way to the Shadowlands. Oh, and Faith? It turned out that she was not real, but a plot of the Shadowlord's to get the King into his realm. And the Shadow Lord says explicitly that you were never important in his eyes, just a pawn that could be used against Lief.