“SAM, RUN!” Castiel cried as he grabbed Dean and threw him into a nearby pillar just before he could reach Sam, cracking it on impact. Sam grit his teeth as his hand tensed around the demon knife. He couldn't leave this to Castiel alone, but he knew Dean was too strong. Even Castiel's eyes were glowing bright with his Grace as he tried to keep Dean at bay. Since the beginning, when he made it back to the bunker, he had to tap into his Grace just to be a match for Dean. Whatever sort of demon Dean was Sam would only get hurt if he got in the middle of them. “SAM!” Castiel barked at him when Dean lunged for his brother again. Sam staggered back when the angel stopped Dean for the second time. “I'll call when it's safe!” Castiel grunted, pulling Dean back with another throw.
Dean was like a wild animal -- raging from the pain the purified blood caused him. The blood cure didn't work. It had brought him to the brink of humanity, but no further. It was just enough to make demon traps useless against him, and after a point, only made him angry and feral. As Dean's black eyes fell on him again, Sam knew that staying would only put Dean in danger. Castiel was only trying to regain control of Dean, but if he kept attacking Sam there might come a point when Castiel might have to make a lethal choice. It was clear Sam couldn't make that choice, so all he could do was trust Castiel, and try to find another way before Dean forced Castiel’s hand. With that final thought, Sam turned and ran.
Dean lurched to go after Sam, but Castiel grabbed him and threw him in the opposing direction once again. Dean roared once Sam made his escape hearing the heavy bunker door echoing as it slammed shut behind his brother, “God dammit, Cas! Would you fuck off!? I don't give a fuck about you right now!”
“I'm not letting you leave, Dean!” Castiel snapped back at him, spreading his feet apart and readying his arms to catch Dean if he made another move to escape.
“You're really gonna make me kill you?” Dean snarled, black eyes fixed completely on the broken angel with the stolen Grace. Sam couldn't see it, but Dean could. The Grace that wrapped around Castiel was definitely not his. The shape was completely off, and it was fading fast as Castiel tapped into it. The second Castiel stopped Dean from killing Sam the first time, he got weaker. Fighting off Dean put a strain on Castiel that he wouldn't be able to maintain. Dean couldn't help smirking at that, “You're not worth my time, Cas. You're gonna die whether I decide to do it or not.”
“You're not killing me today, Dean,” Castiel huffed, “And you're not leaving, either. We'll figure something out, but right now you're coming with me.”
“Like hell,” Dean growled and lunged forward. Castiel sidestepped using the motion to grab and redirect Dean’s punch away. Dean grabbed his wrist and twisted sharply forcing the angel’s vessel to make a loud crunching sound. The twist pulled Castiel closer to Dean who swung his fist into Castiel’s face.
“Dean…” Castiel warned through a bloody swollen lip. He grabbed Dean's shoulder, but Dean slammed the back of his fist into the angel’s face and came around to him again. Castiel grunted when he caught the second blow, and the next, then Dean swung low landing a gut punch. When Castiel sagged forward from the hit, Dean suckerpunched him again. When the angel began to fall Dean caught him and pulled him down as he kneed Castiel in the stomach to maximize the force of impact. He followed Castiel's jolt back from his knee and let him sway back before slamming him forward into a bookcase.
Dean watched as Castiel, bloodied and broken with stolen Grace working awkwardly to heal its unfamiliar host, turned to his side with a groan. His black eyes flashed green for just a moment. There was a feeling in his gut that he didn't recognize. He wondered if it was something left over from his human side. Something that made him spare Sam when he first turned. The same thing that frustrated Crowley into suggesting that he wasn't fully committed to being a demon. He huffed out a breath and turned away from Castiel. Having let out his frustrations on the angel he decided finding another demon to kill would be the best way to take the last of the edge off.
“Dean…” he heard Castiel groan as he walked away. His step swayed as he slowed and shook his head lightly. Dean just wanted him to stay down and let him leave. “Stop.”
Dean fully turned at that, glowering. Even after showing Castiel how much stronger he was compared to him, the broken angel still refused to accept it. His bowed legs swayed his body as he lumbered back toward the angel. It was clear now that mercy was no longer an option. He swung only to have Castiel shift to deflect the hit and use the momentum to push Dean to turn his back to him. Castiel wrapped his arms around Dean in an attempt to capture him again, but Dean wouldn't be taken the same way twice. Dean swung his head back, slamming it into Castiel's nose with a crunch. Castiel released him with a groan and staggered back in a daze from the impact. The angel’s legs buckled and he started to fall forward. Dean caught and kneed Castiel in the stomach once more before flinging him into the nearest table with a loud thud. The demon grabbed the back of Castiel’s head with one hand and the other firmly gripped his shoulder. Dean then proceeded to slam Castiel's face into the table. Again. Again. Again.
Dean could hear Castiel's blood gurgling in his throat as he held him there, feeling his body go slack as his legs buckled under him. Dean took in the sight of the angel in his grip, bent over the table, helpless against him. Dean felt powerful. He felt electric. Castiel, Angel of the Lord, reduced to nothing by his hand. He remembered all the times Castiel beat him, the times he made Dean feel small. He really wanted to drive home that the tables were turned now. Killing him just didn't seem enough anymore. He really wanted Castiel to know how much stronger he was now. How much more powerful he was compared to him.
Dean's eyes wandered down over the bent angel, stopping on his ass. His mind drifted as he found himself thinking that he had him in a prime position, bent over and ready for the taking. Castiel grunted when Dean shifted him to put weight on his legs again, forcing him to stand, but keeping him bent over the table. “Dean…” Castiel burbled, uncertain of what he was doing.
Dean ignored the angel as he pinned him down by the scruff of his neck, pressing his face into the table, and ripped at his collars. He pulled Castiel's trench coat and blazer completely off. The shirt ripped, buttons clicking against the floor, but some more persistent buttons kept the shirt from coming off completely. The tug pulled the shirt open and off so it hung around Castiel's waist, held by two buttons that were ready to snap at another tug. There was a cluster of Grace on Castiel's back, and Dean's eyes narrowed at it. He pressed his fingers into the cluster, ignoring the burning sensation it triggered upon contact with his demonic aura.
In response to the pressure, Castiel let out a wet groan and his wings snapped open. Not his wings, Dean realized. These wings were smaller than the ones Castiel possessed before Metatron stole his Grace, judging from the shadows he remembered. He ran his hand along the semi-exposed tendon between the bone protruding from the angel’s back and the thicker bone above his ulna. The coverts covering it seemed to be thinned from damage in the fall. The angel he stole this Grace from had quite a number done to her wings. He felt a sense of regret that these weren't Castiel's true wings, but when Castiel whimpered from Dean's touch, he found the will to make due.
“Stop…” Castiel coughed, splashing blood onto the table. Dean ran his fingers along the few silken feathers remaining on Castiel's broken wings, triggering a shiver along the bones. He watched as the sparse feathers vibrated from his touch, a light shiver of his own running through him as sparks of pain licked at his fingers from the Grace that made up the stolen wings. “Stop!” Castiel cried out, giving his wings a violent flap as his body jerked to shove Dean off him. Dean's grip on Castiel's nape tightened, and his other hand clamped around the damaged arch of the wing forcing a wail of pain from Castiel. Dean felt another spark of pain bite into his palm as he gripped the wing, but from the sounds of it, Castiel's pain significantly exceeded his own.
“I was trying to be gentle, Cas,” Dean growled as he slid his fingers into Castiel's waistband. He yanked the slacks and boxers down in one pull, exposing Castiel completely to him. “We're friends, after all, but if that's not what you're into, I'm more than happy to oblige.”
“Dean,” Castiel grunted when he heard Dean's belt clicking loose, “don't do this. Not like this. You can't.”
“Stop me,” Dean challenged as he pulled himself loose. He leaned forward, swiping his hand through the puddle of blood by Castiel's face. He stroked his hard cock with the blood, saturating his flesh with several applications.
“Don't do this!” Castiel cried out again as he began to squirm under Dean's grip. His wings flapped frantically, trying to get away, but Dean only lifted Castiel’s head by the grip he had on his nape and slammed it back down onto the table. The strike dazed him long enough for Dean to reach between them to spread Castiel's ass open and push into him. There was a strong resistance to Dean's cock, which he anticipated. The blood helped a little, but Dean still had to be careful not to shove in just yet. He wasn't sparing Castiel, which was evident by the whimpering as he was pushing into the half angel. He knew plunging tip first into a virgin hole like Castiel's would guarantee a painful bend in his shaft. He was enjoying the twitches of pain Castiel's Grace was licking into him, but a broken dick just wasn't in the cards tonight. Castiel shook beneath him, clenching his fists as Dean fed him his cock slow enough to be careful not to bend it, but not slow enough to let Castiel even begin thinking about getting used to his intrusion. When Castiel's rim reached the middle of his length, Dean gave a few small thrusts, in and out, testing the smoothness of his path. Then he slammed his hips forward until they were pressed true to Castiel's, tearing the rest of the way open for himself.
Castiel arched his back as that final thrust slammed a loud cry from his throat, his voice echoing in the bunker. He wasn't given the slightest of a reprieve before Dean began fucking him. The blood already on Dean's cock mixed with the blood in Castiel's freshly torn hole soon made his tight passage smooth as if he was pounding into a well prepped whore.
Castiel grunted and groaned loud as Dean mercilessly assaulted his ass. “Dean!” he cried, pain wracking his hoarse voice. “Dean, please! Stop! Please!”
“Don't act like you didn't want this as much as I have,” Dean laughed at the half angel’s pain, only slamming his hips harder against him. “Staring at me all these years. Doing everything you could to keep me safe. Giving up everything for me. The second April taught you what this was, I know you wanted to do this with me.”
Castiel was in too much pain to even consider denying it. When he shook his head, he only cried out, “Not like this! I don't want to have sex with a demon!”
“Too fucking bad, angel,” Dean crowed, using all of his strength now to tear into Castiel. The table was beginning to give beneath the two powerful creatures, so Dean pulled out just long enough to let Castiel fall to the ground. The demon was on him before Castiel could even realize what happened. He turned Castiel onto his back and was inside him again almost in the blink of an eye. “I would never fuck you as a human, Cas,” Dean affronted, “Maybe I wanted to, but there was so much holding me back. Now, I just want to fuck you till you fucking die .” He gripped Castiel's wings painfully tight, and used them to help him slam his cock into him with all his strength emphasizing his words.
Castiel had bore everything with as much strength as he could up until now, but to think the only way Dean would share any semblance of his feelings for him would be as a demon hurt more than the pain Dean put him through now. Tears fell as his body became pliant to Dean's thrusts, unable to resist anymore. Sobs broke through his grunts and cries of pain as Dean fucked him.
“Fuck…” Dean moaned as he pounded into Castiel, feeling him loosen around him, “Fuck, yes...now you're starting to get into it…” Dean was able to shift his hips now, looking for that special nerve cluster that would bring Castiel's shame home. Dean was rewarded when a jolt interrupted the rocking of Castiel's body from his thrusts, and a moan ripped out through the sobs and grunts of pain. He brushed that spot again and again with each shove of his cock into Castiel, slamming out reluctant moans from his very core.
“That's it, Cas…” Dean groaned, watching Castiel's cock finally begin to respond, “Take it like the fucking slut you are. You're so needy for this, I know you are.” He watched shadows begin to dot Castiel’s Grace as Dean felt himself getting close. He began to fuck the broken angel now for pleasure rather than as a display of power. As far as he was concerned, Castiel was finally his. Now he could focus on getting to the good part.
Dean wrapped his hand around Castiel's stiffening cock, stroking him in time with his thrusts, encouraging the shaft to fill with blood. “I'm gonna fuck you till the end of time,” he moaned, shutting his eyes as he focused on the pleasure around his cock. “You're gonna be begging me to fuck you. Forever, Cas. You and me. We'll destroy this world together. Fuck, it's gonna be so good. You're gonna be so good. My fucking slut Queen. Your ass will be so full of my cum. Forever.”
“Forever…” Castiel moaned. Dean's black eyes snapped open at that. Castiel's eyes were bright with Grace, staring up at him.
“Fuck, Cas…” Dean moaned, pulling Castiel up to him. He slammed their lips together, kissing him hard, moaning into his mouth when he felt Castiel’s arms snake around his neck. He leaned back to let Castiel’s knees rest on the floor and another moan broke from his throat into their kiss as he felt Castiel begin to bounce on his dick. Their tongues burned against each other's, but they wouldn't break the kiss. They couldn't. Their moans mingled together as Dean stroked him and Castiel bounced on him. “Fuck…” Dean moaned against Castiel's lips. “Cas...come. Come with me, Cas. Come with me--” A sharp moan interrupted Dean as his own release overtook him.
Shadows splashed across Castiel's Grace as Dean coated his insides with his demon seed. Castiel cried out as it burned inside him, setting him on fire from within. His own orgasm got away from him, and he splashed across Dean's stomach. Dean let out a roar as Castiel's Grace laden semen burned against his flesh. The pain and pleasure mingled together and the two rode it out, screaming before darkness overtook them both.
Dean moaned softly as a gentle pleasure seemed to break through the fog in his mind. His eyes fluttered as he tried to clear his head, blinking away the blur in his vision. His breathing was getting heavy, but there was another breath huffing with his. As his vision cleared, a bright blue light pierced its way through, briefly blinding him again. He saw Castiel when his eyes adjusted. His face was flushed, but clean of blood and wounds, and his bright eyes focused on a spot between them. Dean shifted, only to realize he couldn't move his hands. He looked down, finding he was back in the chair in the bunker’s dungeon, his wrists bound to the armrests by sigiled cuffs. He also saw Castiel was still naked while he remained clothed. The angel was sitting on his lap with legs draped over his arms. He held their cocks together, and stroked them with a lazy hand.
When Dean looked up, Castiel's bright blue eyes were fixated on him now. “Cas…” Dean groaned, trying to make sense of what was happening, “What do you think you're doing?”
Castiel smiled darkly. “What you wanted, Dean,” he moaned softly, “Giving in. Being a slut for your cock.”
Dean inhaled sharply as Castiel's hand moved with more purpose now. He pulled at the cuffs that bound him to the chair. He could even feel some on his ankles. “Let me go, Cas…” he growled through his moans.
“I don't think I will, Dean,” he mewled as his hips began to rock, feeling the pleasantly urgent pressure building up in his groin, “Mmm...I'll be your ‘Queen,’ but the monarchy we'll build isn't going to be run by you.” Dean shivered as Castiel's dark, low voice washed over him. Their breaths quickened together as Castiel's nimble fingers worked their cocks just right, pulling Dean's focus away from Castiel's rebellion and plunging him into the pleasure of a second orgasm. It was quick and sloppy. The burning of their mixed semen pulled hisses rather than the overwhelmed screams from before.
“Regardless…” Castiel panted as he rested his forehead against Dean's head, “of my feelings for you. You're an ant compared to me. A blip in this world my Father created. Even if we live together for all eternity, you will always be insignificant compared to me. So remember this, Dean...” The angel moved from his lap, glaring down at him. Dean's black eyes widened as Castiel's misshapen Grace flared the broken wings in a wide, dominant display. He was brighter, and much stronger than he had been in their fight. He was recharged and, even though still damaged, magnificent just the same. Then, Dean noticed in his white hot Grace, shadows slithered through his light. Castiel had been tainted by his seed.
Suddenly, Castiel leaned forward, his face so close to Dean's. His voice was low, sultry. He groaned a mere inch from Dean's lips, “I may be a slut for you, but you will always be my whore. ” Before he could register it, Dean's face was suddenly in pain. He cried out as Castiel wiped their burning semen from his stomach onto his face.
Rage crossed his eyes as Dean began to thrash against his bindings, roaring as Castiel sauntered away. He shut the light on Dean, leaving him trapped in the dark to wait for Castiel to need another boost from his demon seed.
Castiel returned to where Dean had taken him, fixing his clothes before he began to dress again. Now that Dean was back in his cage, Castiel considered the new problem at hand. He needed to figure out what to tell Sam.