Skulduggery pleasant
The main characters care called Valkrie Cain who eventually turns out to be the most powerful sorcerer that has ever lived, because when she is going through the surge (when your you pick what magic you can do for your life and you cant change) it picked a new type of magic no one had ever seen before. After some research had been done about it they guessed that it was the closest thing to pure magic and that it was also the most powerful magic they had ever seen! Being able to make light come out of her hands at a horrible heat that burns a human to death in a matter of seconds. And the other main is called skulduggery pleasant who got killed back in 1700 but got resurrected and turned into a villain called lord vile who as a necromancer (someone who uses death to power there magic)
He wore armour which is what he used to channel his magic through (cause necromancers need to channel their magic through an item of some sort) and he fought with the person who killed him who was called Barron vengous because he was so deep in rage because the Barron had also killed his family in front of him before the Barron killed him.
There are a large number of bad guys in these books but the main one is called darquesse
Who is Valkrie Cains true name (a true name is a sorcerers link to magic) when Valkrie finds out about her name she suddenly starts to hear a voice in her head that tells her to do the wrong stuff and when she does, darquesse comes out of hiding in her body and takes full control and wreaks havoc on the world. Like in the book called- dying in the light- when valkrie is under immense pain darquesse talks to her through her head trying to get control of the body to use it for evil but tells valkrie she will only use it to heal her and then give back control of the body to valkrie. When she gives darquesse control of her body darquesse pushes valkrie down as far as she can and takes permanent control and destroys Dublin and then moves onto the world. Eventually, darquesse leaves after a long time of planing to suck her out of valkries body and stuffing it into a completely different dimension and valkrie takes back control of her body but without magic, because darquesse took her magic with her because darquesse was her true name is was also a direct link to magic causing her to lose her magic when her true name left her.