Probably can remove hearts, but I don’t know if he’d go that route (or the writers really) since they did that with Regina and Cora and they don’t want it to get repetitive. I think PP needs the shadow of the boy who has the heart of the truest believer. I think the magic that is keeps you from aging in NL is slowly being destroyed and Henry’s shadow will stop that.
Why would he want a shadow though? A shadow is the absence of light. If they want the heart of the truest believer I don’t think a shadow would cut it. IMO anyway! 🙂