Witch's Boy

Witch's Boy by Michael Gruber
A grotesque foundling turns against the witch who sacrificed almost everything to raise him when he becomes consumed by the desire for money and revenge against those who have hurt him, but he eventually finds his true heart's desire.

Revenge of the Witch (The Last Apprentice Series #1)

Revenge of the Witch (The Last Apprentice Series #1) by Joseph Delaney, Patrick Arrasmith (Illustrator)
Young Tom, the seventh son of a seventh son, starts work as an apprentice for the village spook, whose job is to protect ordinary folk from "ghouls, boggarts, and all manner of wicked beasties." Books in this series: Book 1. Revenge of the Witch -- Book 2. Curse of the Bane -- Book 3. Night of the Soul Stealer -- Book 4. Attack of the Fiend -- Book 5. Wrath of the Bloodeye.