User blog comment:Hunterinpurgatory/How long will Dean and Cas be stuck?/@comment-4920092-20120525130440/@comment-4920092-20120526034436

Wore off? I was under the impression that souls weren't a one-time deal. Once he absorbed them, he had access to their energies. If he used them up, he would have to wait for them to rebuild energy. But souls cannot be destoyed, even by Death, so I doubt that energy blast would have consumed them all.