Spock's heart was racing with barely contained fury as he handed an unconscious Khan over to McCoy. It was all he could do to let go of his crushing grip on the man's arm. Thankfully the doctor was too concerned with aiding the Captain to notice that Spock's hands were trembling despite his clenched fists.
"Spock?" Nyota asked quietly, reaching out to touch his arm gently.
He tensed and jerked away from her, barely able to contain his desire to lash out with a fist. The adrenaline was still rushing through his body at such high levels that all he wanted to do was punch someone. Oh what he wouldn't give to surrender to the great roiling anger he felt and smash Khan's smirking face into a bloody mess.
Spock could see it now, Khan's genetically superior face finally caving in under his fists, the bones fracturing on his knuckles. His face would sink in, a shapeless mess of raw bloody flesh, as Spock punched him over and over. He wouldn't stop until he broke his own skin on Khan's jagged, splintered bones and rivulets of his green blood mixed with the red. Khan would die knowing that he was inferior to Spock in every way.
The thought made him hard.
"Spock?" Nyota repeated, concern in her voice. "Are you okay?"
"I must meditate," Spock barely managed to choke out. He took a shuddering breath and turned away from her, leaving the transporter room.
He barely noticed the damage around him, his focus narrowed down to putting one foot in front of the other. With each step he took, the thud of his boot heel against the floor rang in his ears like the dull thump of a fist pounding into a man's abdomen. He could hear each strike in his head and imagined beautiful black bruises mottling Khan's ribs. Each one would be a testament to Spock's superiority.
His cock throbbed with every step.
Unable to go any further, Spock ducked into an abandoned lab and locked the door behind him. He'd told Nyota that he needed to meditate, but his mind was too scattered and his body too out of control. It would take him hours just to achieve enough calm to try and he didn't have hours. He had to get to sickbay and Kirk. He was going to have to resort to other methods to regain control of himself.
He'd only felt rage like this once before—when Kirk had goaded him into attacking him on the bridge. But even that hadn't been this all-encompassing. Khan had threatened everything that Spock held dear and taken away his closest friend—his only friend—and Spock's primitive side had taken over. He was now no better than the ancient Vulcans, enslaved by his emotions and driven by his most base desires. That meant that there were only two options available to him for a fast resolution—fighting or fucking.
Spock pushed his pants down just far enough to get a hand on his hard cock and immediately began stroking it. His grip was tight, nearly painful, but that was good. Pain was good. He leaned his back against the wall for support and drove his dick forward into his hand with sharp snaps of his hips.
It didn't take long, he was so worked up that it only took a few thrusts before all of the heat in his body gathered low in his stomach and he came with a roar. Spock's eyes closed as waves of pleasure washed over him and he imagined himself standing over Khan's broken body, cock in hand, as thick streams of green-tinted come spilled out and streaked the bloody flesh. The image of his come marking Khan's cold dead body was so visceral that Spock tensed as a second orgasm hit him.
Drained, he slid down the wall until he was sitting on the floor, still shaking with the aftershocks. As his heart rate slowed down to normal, he could feel the fog lifting from his mind. With clarity came shame as he stared at the mess he'd made on the floor. He couldn't believe the thoughts he'd allowed to take over his mind.
Khan had truly taken everything from him, including his dignity.