Nightmare Fuel / The Chronicles of Prydain

• Reading the final book, it seems that at least part of why actual displays of full-force magic are so rare in the series is that Prydain-style spellcasting results in this when fully unleashed.
  • In Taran Wanderer, Morda transforming the protagonists into animals is plenty creepy. Doli, who was turned into a frog, seems to constantly be ill, spasming at one point, and nearly dies from lack of water. When the rest are caught by Morda, he creepily ties them all up before enchanting them one by one, gleefully musing to Taran about how he wants to pick a form for him that's particularly humiliating and easy to enslave. And when Taran manages to free himself and fight back? Morda used his magic to make himself unkillable. Even more scary, Taran only found Morda's Soul Jar completely by chance. If he didn't have it with him, not only would it have been impossible to kill Morda, but there would have been nothing to protect Taran from the ensuing attempted transformation spell after stabbing the guy didn't work.