What's the Name of That Book??? discussion

[SPOILERS] It turns out that the "true name" they have been gathering syllables for is a ruse made by the wizard king as a red herring and doesn't work. The king is defeated/killed because the heroes (one male and one female) blow up the mountain the king's fortress is built on because it turns out the mountain is an ancient mine for a highly explosive material. The female protagonist is an athletic type. The series has a human-like race that is able to detach limbs and body parts at will and still be able to magically manipulate them. This particular race is always treated with suspicion because it is assumed they are all spies for the evil wizard king. The evil wizard king has a resort paradise for his enemies who become a big enough pain that he gets rid of them by inviting them to this resort where they will enjoy an easy life but can never leave.

I read this series around 2009-2012 in my middle school years. The books were physical, and I'm pretty certain it was a series, not a standalone book.

This sounds like the "Beyonders" series by Brandon Mull.

A World Without Heroes for Nachelle's suggestion.

You both are correct, this is exactly the series I was looking for. Thank you so much!