First when they killed off the alphas i thought that was dumb because they made them so strong. then eve was the one that created all monsters. She was more powerful than angels. She owned purgatory. Then a pheonix a creature that she created kills her. Plus since she owns purgatory would'nt she have the power to use the souls if she wanted. they built the whole season around eve and at the minute go the war in heavon. Plus if the souls give so much power shouldn't crowly be more powerful than the castiel because he has the souls from hell. plus wouldn't lucifer have used the souls to fight the heavon in season five or lilith or azazel before him.