66 Seals

        These seals were created by God to secure Lucifer in his cage in the depths of Hell. There are over six hundred different seals however only only sixty six need to be broken to release Lucifer from his imprisonment. The first and last seals are very important and have to be a certain type of seal.

       


The first seal is broken when a righteous man sheds blood in hell. Dean is the one who breaks this seal. When Lilith's hell hounds drag him to hell. For thirty years down there he was tortured and ripped to bits then he finally decided to do the torturing. The demons intended John Winchester to break this seal but Dean did it instead.


Then the final one is called: "The first Demon will be the last seal." So Lilith, the original demon Lucifer created must be killed for him to rise to Earth. So Sam ends up killing her breaking the final seal, and starting the apocalypse.
Other seals which are broken during this time are as followed:
Rise of the Witnesses, which are the ghosts of the people who were killed and not saved by the brothers.

Raising of Samhain, the pagan god which kills people on October 31st unless people are covered with blod and gore, also known as a mask.
Ten species going extinct in Key West
Everyone in a fifteen-man fishing crew going blind in Alaska
A teacher in New York killing sixty-six students
Death of two reapers on the night of the solstice (unbroken)