The Darkness (Supernatural)

The Darkness is an antagonistic force first appearing in the Season 10 finale of the CW television series Supernatural.

It is an ancient, primordial force that existed before God came into being. After coming into being, God, along with His Archangels, battled the Darkness in a destructive conflict before locking it away using what would later become the Mark of Cain, which he entrusted to Lucifer. However, Lucifer became corrupted by the Darkness as it asserted its influence upon him and led him to rebel against God's command to bow down to humankind. After Lucifer was banished from Heaven, he transferred the mark to Cain who, many centuries later, passed it to Dean Winchester.

The Darkness could only remained imprisoned if the mark was passed to another person. Thus, the removal of the Mark of Cain from Dean, caused by a spell cast by Rowena at Sam Winchester's behest, had the unfortunate consequence of unleashing the Darkness upon Earth. Once freed, the Darkness achieved a gigantic size and descended upon the Winchester brothers as they tried to flee in the Impala, leaving their fate uncertain.