The sight of Castiel slain, bound and broken to that chair, was the most horrifying thing Gadreel had seen in his long and painful life.
He thought he knew pain when he had first been brought in for punishment, his mate forcibly restrained to keep from coming to his defense when his sentence was first announced to the entierety of the Host. Their fledgling, the first born who hadn't been made directly by their Father's hand, had been taken from them, and his memories altered. He would remember his other parent vaguely, as a brother only, and no longer under his care, but Gadreel . . . all memories of Gadreel were to be erased completely. To keep him pure of the evil his parent had done, they said, to save him from corruption.
He wondered if any other fledglings had been brought forth after his failure. The thought had left a hollow ache within him.
He thought he knew pain when he had been told that his mate had fled Heaven after an attempt to free him. Apparently after arguing for his release, and failing, his loyal mate had tried to retrieve Gadreel himself, only to be swatted down violently by Michael and Raphael themselves, since no one else had the power to keep him at bay. Thaddeus had taken great joy with taunting him with the information even as he doled out a more physical type of agony. And again later, when it was said his mate had perished.
The following millenia of tourture, his fall, none of it compared to this.
He had been resting in the back of Sam Winchester's mind only to be violently brought to awareness when his vessel was thrown and then rendered unconcious. The first thing Gadreel saw when he woke was Dean crouched over the limp body of a dark haired man, hands cradling his face. The older Winchester's voice was brittle in a way Gadreel would never have imagined.
Gadreel's eyes focused on the body, and it was then he truly saw who lay there. Even without the charcoaled impression of wings that should have been surrounding him, saw who he was. Changed though he was, mortal though he was, he knew him, he had known him since his very creation, so of course he would know him even in death. Gadreel's decimated wings flared in shock, in recognition, and in the urge to shelter even though it came far too late.
He slowly climbed to his feet, his eyes never leaving Castiel.
His Castiel, long grown and now twice stolen away from him.
Dean rose and took a step back. He turned to Gadreel then, wrecked and on the verge of tears, seeing only his brother and not the angel currently in control. "Sam, he's gone."
No, he refused.
He strode forward on long, borrowed legs, filled with intent. A palm settled over Castiel's bared stomach, over the worst of the wounds and began to pour all the Grace he could spare without losing Sam as well. He knelt beside him as he worked, wings arching forward in protection, even if it was such a pitiful amount. Light flared as he healed the body and summoned Castiel back to him, called back that core spark that was unique among angels, the only one of it's kind. It was small and fragile, that tiny spark somehow stripped of the grace gifted to him by his parents.
And so Gadreel carved out another piece of himself and gave.
Author's Note: I'm so enamored with this fic, even if I don't know where the fuck it flew in from. I've long since learned to never argue with my muse. And let me tell you, she PUNCHED me in the face with this one, and refused to let me ignore it. So strap in kiddies, I'm about to brave tropes I've never touched and a pairing I've never dabbled with (and frankly have never found before). Here goes nothing.