The Darkness is coming

The Darkness is coming is a mantra often repeated - in one form or another - by beings aware of her release and original intention to destroy everything that exists. Amara herself, when she wanted to warn a few of God's creations, carved the same message onto Castiel's chest and apported him where she wanted. One particular variant was also mentioned a few times: "The Darkness is out there".

It serves as a form of warning, similar to another mantra common to apocalyptic scenarios: "The end is coming". However, unlike that mantra, those who knew of the Darkness' release showed distress when they heard that the Darkness was coming. Even the reaper Billie, who wanted to refrain from assisting Sam and Dean, became visibly agitated when Dean spoke of the Darkness' presence on Earth.