"...Dean! Stay back!" Castiel boomed, his voice crumbling and weak. His angel blade clasped weakly by sweaty fingertips. Images of thrusting the blade into Deans soft flesh and watching the crimson flood from the wound and shouting a shaky, raw exorcism forced their way into his head and he simply was at loss for the strength to grasp it tightly enough to wield it effectively. He couldn't possibly do that. Because that would mean making up his mind. It would mean giving up on Dean Winchester; the small unassuming human who became so much more than that. He wasn't prepared for the battle that would undoubtedly ensue and inevitably end in bloodshed. He pondered grimly; what would be more agonizing? Watching whatever light that remained drain from those glistening emeralds he'd come to know so well over these years, or fading away staring into a cold dark empty abyss that revealed all that he was missing?
Surely something had gone horribly wrong whilst Sam sent Castiel upstairs to retrieve more holy water and fresh needles. With Sam nowhere to be found and presumably murdered, it wasn't looking good for Cas, whom may as well have taped a piece of paper that read, 'I am utterly defenseless to you, please destroy me.' to the back of his trench coat. He clenched his jaw, carefully awaiting the next movement of his friend turned foe, silently begging him not to initiate violence with his desperate and drained crows feet. "Cas..." Dean chokes out, his voice thick with tears. He flinches at the words before acknowledging their meaning and the soft broken affectionate undertones of his voice.
He can feel his chest melting and caving in on itself as Dean takes hesitant footfalls closer to him. An infinite and seemingly boundless plethora of scenarios had flowed through his veins into his throbbing skull, and yet not a single flash of misplaced anticipation met what Castiel would have never predicted; Dean's lips crash landing ever so delicately on his. It's disorienting and passionate and beautiful and it's everything that was always meant to be between them and still somehow eluded them and slipped through the cracks of bashfulness and hard times. It's one of those complex, wondrous magnificent feelings that humans seem to be comprised of, and it feels incredible. Love. He was in love. He was so utterly consumed by that moment of pure affection whirling about the hot muggy bunker air, he hardly was present to feel the sharp pinch of the first blade slashing and plunging into his abdomen, and suddenly he was distant, a vague chill settling on the surface of his skin as blood gushed rapidly from the mortal wound left from the blade.
Dean held his gaze, a sadistic smirk creeping across his lips. Castiel was foolish and vulnerable and nearly human, and was now to die by the same sword his dynamic and gut wrenching emotions wielded to his throat. His eyes fell upon his angel blade, clattered to the ground unceremoniously and long useless to him now. The lights began to dim within the deep stolen indigo that embodied Castiel's very being, they caught a glance of a satisfied smirk contorted into Deans face. As he drifted further he pondered gathering whatever remnants of strength he could come by to utter a croaky 'Why?', but It'd be an infernal task. He knew exactly why. He knew that Dean Winchester died a long time ago. He was long gone, and now so was he.