The Three-Headed Dagger and the Kings Son: (Three-Headed Dagger Series Book 2) by Henry Regnault

It’s been five years since Cadence Mage, Christopher, and Tidus Brack were placed inside the Three-Headed Dagger.
Little Jenny, trains with Graves and Meadow to master the lightning magic and powers her father and uncle bestowed on her.
Two demons who escaped from the battle at the broken church are now feeding on humans knowing that Jenny is looking for them.
Cadence Mage, demon hunter, along with old and new friends will battle new demons and a powerful evil nothing like he has ever faced through the centuries. He will meet his father the king for the first time and witness his niece Jenny embrace her dark destiny.