The tragedy of Puck is worthy of note:
Born of some long lost gods, defeated by the All-Father, the young god was a small child when he was found by Grimnir and, in a show of remorse and compassion, the All-Father took in Puck as his own son, raising him and trying to guide him, and treating him like his own flesh-and-blood. But the other gods did not share in Grimnir's kind-hearted ambition, at least without Grimnir prompting them to try, as they found the boy an unsettling and awkward addition to their pantheon. Furthermore, those that tried to show him patience had their kindness returned to them in jokes or, worse, what the boy considered pranks and tricks. To Puck, nobody seem to be able to take a good joke.
Puck stole treasures and artifacts from immortals and mortals alike, often "borrowing them", as part of his greater schemes to humiliate his kin and nobles, preferring to target the prouder and nobler most, but often going too far in his japes. He accomplished his feats with shape-shifting, magic and the ability to separate and control shadows from their owner's. His schemes resulted in unnecessary misunderstandings, accidental deaths and even wars between furious monarch. His wicked sense of humor and disregard for the laws of man, nature and gods are legendary.
A great smith was building an impenetrable wall for the New Gods with the promise that he would be granted dominion, power and protection within the wall. He also wanted Kleeona as his bride, the Sun and the Moon. The gods took council and Puck created special conditions: If the smith could built the wall with only help from his horse, in one winter, he would be granted his prize. After all, the smith had said it would take years and, under these conditions and if he failed, he'd build the wall for free. The smith agreed.
The gods had underestimated his horse though and, with only a few days left in winter, he seemed on the brink of success. The gods demanded that Puck fix the situation, scaring him into action and fix it he did. Without his horse, Puck knew the smith would fail. So, he took the shape of a mare, luring the smith's stallion into a chase, throwing the smith from it. The smith died before he could finish the wall and, more disturbingly, the stallion caught Loki in mare's guise. The mare gave birth to the Six-Legged Horse of Legend.
The smith was a friend of Skao and demanded retribution in the form of laughter or the life of Kleeona. None could make her smile. Save Puck. Puck managed to make her smile, saving the life of Kleeona, but no one was thankful after he had ruined the wall they needed.
Puck was also responsible for the creation of Fenrir and other horros. But it was his part in the death of a son of Kleeona and Grimnir.
So, the story goes, that Puck wished for nothing more than to be the favorite son of Grimnir Blue-Cloak. He was not the best or strongest or brightest but he was capable of playing the gods against each other. He sought to prove himself the most cunning and to diminish the standing of rivals for his father's approval.
Grimnir Blue-Cloak had twin sons: Baldric and Hodric.
Both were beautiful and kind gods, of light and life and hope, and were perfect. Save Hodric who was born without eyes. They were both beloved by their mother and the other gods. Except for Puck, who was annoyed with them, especially Baldric.
As if sensing Puck's intent, Kleeona saw no love in Baldric's future. She hurried to protect her son, using her spells to make him immune to all animals and plants. She overlooked mistletoe. And, overhearing Baldric boast he was save from all save the plant, he made a scheme.
After all, Baldric' invulnerability meant that gods would often attempt to strike him down for folly, failing of course, but trying again. Blind Hodric was bullied into playing a game in which he tried to shoot arrows at his twin brother. Puck handed him one. Made of mistletoe.
And it flew true. Baldric was struck in the heart. And he fell dead by his blind brother's aim.
When the New Gods realized that Puck was to blame, though he claimed to only want to hurt Baldric's pride, they were quick to punishment. They weighed this crime with all of Puck's other crimes, quickly, and in their fury they set to work. They beat him down and bound poor Puck to three stone circles imbued with rune magic to keep him from changing shape. They then set a poisonous serpent above his head so, as venom dripped from its fangs, it would strike his face and cause him intense agony. His most faithful lover, Syg, took it upon herself to hold a bowl, catching the venom, but, when it becomes to full and she must tear it out, he has to endure the venom in those moments.
But that is and was not the end of Puck.
Perhaps related to the gods of his heritage or created by his own hatred or even from another realm, Puck's madness spawned or was spawned by something unusual. As Puck lay in his prison, he heard a voice. A familiar voice. Like his own but different. It was his old shadow.
It begged to be released from him. That it would help him. Puck quickly agreed. But the shadow betrayed him. It abandoned him.
Not even Puck knows what it was. It had been his shadow. But, at least after that, it was something else. It had its own motives. It called itself Darkheart.
Darkheart wants nothing less than to wallow in the suffer and hate of the world, to see it come to chaos and ruin, as it moves from host to host, and sets unknowable plans into motion. Its ultimate goal is unclear but, a prophecy says that, in the end times, Puck will finally be reunited with his shadow Darkheart and, with his progeny and an army of all the enemies of Narya, will defeat the gods, destroy the world, and a new world will take its place.