I read this novel series (not sure how many books) in middle school so it would be 2010 or earlier. The boy, main character, had the ability to shapeshift or had some sort of magical ability. He was either an orphan or didn't have a good home life.
The biggest distinction I can remember is that there was a cat(s) that would periodically give him signs about when things were going wrong.
This description here (Book about a boy with magic ability - shapeshifting or transformation) also seems familiar.
Books I've ruled out:
- The Switchers
- Dragon of the Lost Sea
- The Shapeshifter series