User blog comment:ImperiexSeed/Supernatural Mysteries/@comment-3481504-20120404154634/@comment-3045936-20120408200910

After becoming King of Hell. Also Rudy said human souls don't leave Hell not Heaven so easy that no demon could do. Also, if Azazel could make deal like using the deal without a soul at all, then why even make the deal with all the special children? He could have just strong armed Mary into giving permission to enter bady sam's room, but he still sealed the deal with a kiss. The Salute to Supernatural season 7 said that Crowley is a different Ruler of Hell than Azazel, not stronger or worse but different with different powers than what Azazel had. So maybe Crowley has now the power to a degree revive people. Also, Crowley has arcane knowledge and that might help after his increase in power after his rise to power in Hell.

Furthermore, the Salute to Supernatural for season 4 ask Eric Kriple this question and I cannot believe I forgot this. He said every demon able to use Crossroad deals, have to start the process like any other deal using the soul as the key to remove the red tape from the Demons power to cast the dealers wishes however he says the demons only needs a soul as he key not as a payment. But, often takes them. He also said its easier to revive the dead from Heaven than Hell his own personal idea.