Bahamut roared in rage and frustration as he felt himself unceremoniously banished from his sister’s realm. He’d been reckless and suffered a stinging defeat as a result. The image of her outstretched claw, spewing forth shadowy magic, was still fresh in his mind as he was blasted through the planes of existence. Somewhere, far from Tiamat’s realm, a lazy cloud drifted across an otherwise gray sky. Suddenly the air shuddered as a gash rent through it, opening a portal from another reality. Moments later an incandescent writhing ball of platinum scales, claws and teeth bound in shadowy tendrils hurtled through the hole. Almost as quickly as it appeared the portal resealed. 
Bahamut twisted and contorted in the air but was unable to right himself. His wings were less than useless bound as he was. Like a bird caught in a net he plummeted towards the mountain below. A casual observer may have thought a meteor had punched through the atmosphere. A deity of his power should have easily been able to stop their decent with a thought, however something was wrong about this place. He could barely feel his connection to his worshippers and therefore his powers. As he careened towards the mountain, the glow of his divinity continued to dim. Bahamut tapped into the last of the reserves of his divine might and channeled into the shadowy binds that held him. The tendrils started to weaken as the light pushed against them but not before he crashed headfirst into the mountainside. Slamming into a rockface at that speed would have killed any mortal dragon, but Bahamut was the god of good dragons. Instead, his impact cannoned him through the peak and the one behind it before he was sent tumbling down towards the foothills. Behind him the summits shuddered before sloughing off in avalanches of rock and snow. At some point the bindings dissolved and he was a rolling mass of limbs. He eventually came to a stop after rolling into a yawning cavern. Bahamut felt the cave shake as he slammed into the wall on his way in. He lay there for a moment in an undignified mess. He let out a pained groan and just lay in the dirt getting his bearings.
The first thing he noticed as he reoriented himself was that he was laying in something wet and sticky. He rolled over and peered quizzically at the cave floor. The liquid was a translucent mess with streaks of yellow throughout. Here and there small bits of stone… no shell floated around. His stomach sank when he realized he had crushed some creature’s nest. Judging by the size of the eggs they were likely from another bird or lizard of considerable size. 
A quiet rustle drew his attention to two sets of red eyes staring at him from the darkness. This must be the creature who’s nest he’d inadvertently destroyed. From what he could tell, it was some sort of dragon that stood nervously on a bolder nearby. Though black in color, it differed from the ones he was used to encountering in his home world. This creature lacked wing membranes, but still had the musculature of the wing itself. It seemed to rest on them like an extra set of legs. In the dim light it wasn’t possible for him to make out the sex of the dragon before him, but assumed it was the mother of the clutch of eggs. Bahamut took a steadying breath before calling upon his divine magic to restore the shattered orbs, or at least he tried to. The very fabric of the plane seemed to smother him, dampening his magic. His claws glowed a soft silvery light before sputtering out. Bowing his head sorrowfully he gestured to the broken eggs. “I’m sorry little one for the irreparable harm that I have done. Were it in my power I would restore what has been lost. For now, all I can give is my condolences. As for my sudden appearance…”
Despair observed the foreign dragon before him. The initial panic at being spotted quickly faded as Bahamut continued his long-winded explanation. The words meant nothing to Despair, but he could tell the dragon before him meant him no harm from the placating manner it was waving its limbs. Despair had meant to make a meal of the eggs he’d found, but the sight of the mammoth dragon before him whet a different kind of appetite. His prey obviously was unaware of the danger it was in. Smiling Despair sat on his haunches and waved his longer set of arms in snappy motions. He beckoned the massive dragon closer. He hoped that Bahamut would get close enough to spring his trap.
“So, you see, it was my own hubris that got me into this situation to begin with. I shall have to ask you a favor in this trying time, for I need a place to rest before I can attempt to return to my home. What do…. Hmmm. What is it that you want little friend?” Bahamut asked as he noticed Despair waving his limbs. He padded closer and leaned in. “I’m sorry I don’t underst—ACK!”
As soon as Bahamut is in range Despair loosed his first jet of cum. The seed landed directly in Bahamut’s open mouth, quickly coating his tongue in the fluid. The second, third, and fourth shots came out in rapid succession. Before Bahamut reacted he’d already taken a shot to the eye and two more in his maw. When he finally had the presence of mind to rear back, he caught a jet on the snout. Soon all he saw, smelled, and tasted was Despairs essence. The large bolus of cum he ingested immediately began to work their insidious effect. It quickly absorbed into Bahamut’s system and activated the dragon god’s submission response. The dregs of magic that were working to heal his body was inadvertently recruited to amplify the arousal and submissive centers of the platinum dragon’s mind. So distracted was Bahamut by the sudden assault that he lost track of Despair as he quickly scampered down from the rock. A rational part of his mind was ringing the alarm. With a moment of panic, he pawed at his face and mouth to clear it of the vile slime.
Despair knew his opportunity was now. With practiced ease he darted underneath Bahamut and between his hind legs. He spotted his target beneath the platinum god’s tail. The area around the larger dragon’s hole was scaleless, vulnerable. Despair scampered up the bigger dragon’s hind leg and positioned himself. The small dragon’s cock rapidly grew to full hardness. The tapered tip making entry an inevitability. With a grin he jammed himself into the opening. Bahamut let out a pained roar at the sudden penetration, but it was too late. Despairs cock had inflated and was blasting his innards with more cum. He tried to shake the smaller dragon off to no avail. His struggles only served to milk Despair’s cock of more cum. With a growl he slammed his tail down to crush the offensive little beast. To his chagrin it only served to jam Despair deeper into his ass. Thrashing about he clawed at his rear but the black dragon had latched on tightly with its appendages. Though he was able to tear of a one of the limbs, the dragon kept pumping him full of more cum. He could feel it subverting his will. The divine magic wisped out of him as he groaned in a barely contained pleasure. Mustering his will Bahamut tried to bolt for the cave entrance. His fore claws dug into the stone before the cum’s hold on his mind was too much. His chest heaved and he fell forward. It was only now that he noticed his body showed the physical manifestations of the corruption. All over his body tendrils of darkness crept across his skin. The once radiant platinum scales tarnished as more and more of Despairs influence took hold. Unconsciously his body locked into a breeding position. His tail hiked high over his back to give his new master better access. With each thrust from Despair, his cock crept further from its vent.  Eventually all he could focus on was the pounding in his ass and throbbing of his cock. His master milked his shaft with his tail making the big dragon leak. Bahamut could sense his orgasm coming. A small part of his psyche screamed at him to resist, that if he came it’d be the end. Bahamut could have held on, could have escaped but at that moment Despair decided to slide his tip into the dragon god’s shaft. The new sensation was too much. All Bahamut knew for the brief moment before he truly became a cum receptacle for the little dragon was orgasmic bliss. 
For his part Despair gloated in his victory. At first, he didn’t notice the magic seeping into him. Wherever it touched him, he grew stronger. The small dragon enjoyed more strength and stamina than it had ever experienced before. With this constant source of sustenance so plentiful and pleasurable, Despair resolved to feast to his hearts content. 
Days passed to weeks to months before Despair had his fill. One day he scampered off in search of other prey. So entrenched was Bahamut as a breeding bitch that for long hours he lay squirming, well-bred hole winking in need. Eventually his ravaged body recovered. He lost track of the days as he suffered from withdrawal from the Despairs cum. On the night that he deemed himself strong enough to leave he noticed two sets of eyes watching him. The same four eyes he’d seen so many months prior. With rage he leapt at black dragon before him. His jaws snapped forward, ready to rend the beast in front of him, but something pulled him back. Like a dog at the end of its leash his head snapped back a moment before his tongue shot out. His tongue licking the throbbing shaft in front of him. It was then that he realized the extent that the cum had effected him. Then, then he truly knew Despair.