Dean Winchester is saved.
The Angel of Thursday did not echo it through the Heavens this time.
There was no valiant effort, no glorious fight. Where once there had been great light of unyieldingly holy power, there is now a hollow emptiness. An echoing chasm brimming with horrors.
Something happened to him in Purgatory.
The first thing Castiel remembers of Purgatory is darkness. Utter, inescapable darkness that seeped into his grace. Icy tendrils of the monsters within stirring faintly. But the moment Castiel landed in Purgatory, he was in complete darkness, and for a moment, he felt his grace was gone. Just for a moment. And then he felt a searing tear.
In the darkness, Castiel reached for Dean. Always for Dean.
A voice from within huffs angrily, not so gently reminding Castiel's grace that there is a job at hand. Standing in the small cabin, Castiel reaches to place his on the items before him. Holy water. Borax. The knife.
Over and over again, Castiel's pulsing, fractured grace repeats the ritual. Needing to check once more whether he is a monster. His grace shifts in his vessel. It's simply unlike anything the angel has ever experienced before. He knows that this is the only reason he is alive.
Only the Michael sword could perform such an act. Could facilitate such a miracle.
Castiel has to be certain. Deathly certain.
Now that his grace is occupying Dean Winchester as a vessel.
Dean is always conscious while Castiel occupies his body. It goes against everything he ever stood for; he always said that he would NEVER be a meat-suit for those feathered dicks. But Purgatory changed things. It warps perceptions, and dissolves facades. It is a horror that surpassed even Hell for Dean.
Dean hadn't known Castiel when he pulled him out of the Pit. He barely remembers the moment in fact. But every second of watching Castiel's grace languish in Purgatory will never leave his mind. Not only was it his angel. The one he knew he would never leave; the one he would fight until his own end to protect. But the process itself was physically painful to experience
There will never be a moment that Dean is not plagued by the image and gut-wrenching, heart-stabbing pain of Castiel's grace dying.
Each time a fragment was ripped by the malevolent forces of Purgatory, a new darkness settled into Castiel's eyes. A new hunger began to ravage the corporeal form still irreveccably attached to his disintegrating grace as Jimmy had not been in the vessel made after his likeness for a very long time.
Dean remains conscious while acting as Castiel's vessel because he doesn't know if he can trust the angel. He's not sure if it's possible to silence that rage, the fire that burns so intensely and razes anything it touches, Dean can't be sure that it will be kept at bay now that it has been awakened inside the angel's wrecked grace.
So they perform the rituals.
They are not monsters.