Well, here is a story that no one asked for or was expecting, but you are getting anyways. I came up with it on a whim, so let's see how good it is. Here is a bit of background for the dark dragon that caused so much suffering.
After so long tormenting humanity and artificially prolonging his lifespan, the dark dragon Loptyr had finally been dragged to the deepest depths of Hell where he belonged. Yet even in torment, he still managed to maintain at least a portion of his smug and self-satisfied attitude. Why? Simply because in life Loptyr had been a paranoid bastard who came up with a number of contingency plans in order to prolong his reign of terror on the world. While most of them were now rendered obsolete, two remained in play in the land of the living. It would take a while for them to become viable, but in the end, they WOULD spread his will across the world of man.
One might expect, for a being to be so ruthless, he had to have had an exceedingly tragic backstory involving humans having wronged him. Nothing could be further from the truth. No, Loptyr had never had any redeeming qualities, he was born a psychopath and a narcissist to boot. His worldview was egocentric from start to finish. True, not all psychopaths are evil, but Loptyr never had any interest in doing anything good, ever.
Loptyr was born into the Earth Dragon clan, as the youngest of four princes and the least likely heir... until he arranged their... tragic... accidental and incidental deaths. He had no reason to do it, his family had treated him quite well. The same with the human race, he never really saw their negative traits until he began to plot against them, thus giving him justification in his actions. No, he had nothing truly against his family and the humans. They were simply in his way. At his very core, Loptyr was a creature of malicious arrogance who believed he should be in charge of... everything. And he saw the human race as a conglomerate of inferior beings who thought they were at the level of dragons.
And so, for no particular reason at all, he plotted the destruction of everyone around him. His ever action from birth to death was done in an attempt to engrave what he saw as the truth into the world's slate. He was the ultimate lifeform, the supreme being.
He became the king of the Earth dragons at an exceedingly young age for their kind, and even sired a son, (if quite reluctantly on both parties part) a son whom he named Medeus.
Naturally, he did not get along very well with any of the other dragon clans. In particular, he utterly despised the Divine Dragon queen, Naga. From the ver beginning, he perceived her as his foil, his polar opposite. And in this particular case, opposites most certainly did not attract.
Thus, he hated the fact that Medeus chose to become friends with her. In Loptyr's view, they were close to one another, FAR FAR to close. Despite being given evidence to the contrary, Loptyr believed until his dying day and beyond, that the queen's daughter was his grandchild. (She really wasn't). Still, he would have been remiss not to take advantage of the situation. He made sure that Medeus was visiting her when she gave birth (in human form, in hopes that childbirth in human form would help to circumvent the inherent madness that was encroaching on all dragonkind). Then had one of his retainers collect some of the blood spilled in the birthing, just in case he could find a use for it.
Naturally, the unending depths of his spite for everyone who wasn't him, led to the destruction of his tribe. He actually did heed Naga's warning about the encroaching madness and took advantage of it. He didn't simply disregard those warnings, instead, he plotted the mother-of-all tantrums against fate underneath an air of arrogant dismissal. He thus chose to occasionally take a manakete form when no-one was around in order to stave off the madness, and took advantage of his clan's insanity when it finally decended in order to lash out against all of his enemies.
Before doing so, he sealed a part of his soul into a dragonstone tainted by dark magic, and gave it to some of his closest followers, who he had helped maintain a semblance of sanity and ordered them to keep away from the final battle. During said battle, he manipulated Medeus into fighting him directly and to the death. Medeus won the fight, but in his death throes, Loptyr bit his son on the neck, and poured as much of his malice as he could into the wound. Knowing that, over time it would heal, but still help to slowly taint his son's worldview. His influence would help Medeus's inevitable corruption along as he came to see how loathsome human beings were.
Though, Loptyr had to admit, the human race was not without its uses.
Just as he had arranged his own death, he arranged his resurrection. His surviving followers used his dragonstone in order to reanimate him as a dark dragon. They didn't need to know that this act would cost them their lives, of course. Soon thereafter, he used a pair of humans to further his ends. He learned of a mad alchemist in the Thabes who was looking for dragon's blood to use in his experiments. Taking the collection of Naga's blood he had kept hidden, he tainted it mixing some of his own blood with it, and putting the mixed bodily fluids somewhere where Forneus could find it, (though not necessarily easily).
Thus was born the artificial son of both himself and his nemesis. This creature didn't need Loptyr's outside influence, Grima was born with the exact same mindset as his father. And unlike either his father or half-brother, he didn't have to go through a process in order to become a dark dragon. He was born as one. Though... considering his mixed heritage, he was less akin to a natural creature of the dark and more like a fallen angel, one of those beings we refer to as demons. A fallen dragon, or perhaps a more fitting name for the creature was a... Fell Dragon.
Soon after Grima's creation, Loptyr made his deal with Galle, sealing his essence inside a tome and leaving the continent entirely.
Loptyr kept his memory of these machinations in his memory locked, even while in torment. For they gave him satisfaction, knowing that his legacy of hate lived on. The only way that the torment of Hell could make him lose his hope and prideful spirit, would be for both of his sons to join him in the pits of Hell. But of course, there was no chance of that ever happening, now was there?