There once was a Guardian, who's Light shone as brightly as any star. All who gazed upon them basked in their warmth and were protected from the Darkness by their mere presence. Everywhere they went, the Darkness quailed from their resplendent Light. The Eliksni, scavengers of metal and tool, shrank from their questing eyes. The Hive, ever hungry and plotting, ran in terror from their burning touch. The Vex, machines lost to all but themselves, fell in droves before their piercing cannon. And the Cabal, the shield of the Darkness, crumbled beneath their boot. All of this... displeased the Darkness. It did not take kindly to its attempts at coercion and its very envoys, being interceded by this... beacon in its perfect world. So it devised a plan. A simple plan but cunning in its execution.
One day, the Guardian stumbled across a dying Eliksni. Its mask was destroyed and it leaked ether into the air; wisps of its essence gleaming silver to their burning gaze. The Guardian pitied the Eliksni, as they cared for all things living (even those who called the Darkness their home), and reached out for its hand, to comfort it in death, only to recoil when it sneered at them and spoke. And when it spoke, its voice chilled them to the very bone.
"Emissary of the Traveller, Guardian of my Creator, I am humbled by your very presence. Permit me, if you will, an audience with one as bright and shining as yourself." The Guardian had never heard such a voice. It felt like oil dripped into their ears and its very cadence spoke of corruption. Reaching for their gun, their gaze narrowed.
"And why should I permit such an audience with one such as you? You, who take possession of the dying and speak the very being of corruption?" asked the Guardian.
The possessed Eliksni chuckled, its voice teasing and insulting. "Because you are curious, of course. Why else have you not shot me?" Pushing itself gingerly into a seated position, it stared into the Guardian's eyes, its gaze deep and calculating, cold and fathomless. "Please, sit. I do not wish to speak on uneven footing."
Ever wary and going against their better judgment, the Guardian crouched, their fingers never straying far from the cannon on their hip. "Then first speak of your name. Who are you and where do you hail? How have you taken possession of this doomed soul?"
At that, the Eliksni laughed, dark and ominous. "My name is innumerable, as I have been called so many things. As for where I hail... you already know." Putting all four of its hands together, a bubble of void energy began to blossom forth from between them. "For every light, no matter how bright, there is a Darkness. Your 'Traveller' is that light, and I am its Darkness. When it came into being eons ago, I was birthed alongside it; always chasing, never an equal." With wry smirk, it crush the void bubble between its fingers and watched as the sparks of energy flitted off into the air between them. "As for how I can possess this... puppet, it is of me and I am of it. I know all of its secrets, its life, as if they had been my own. Because it has embraced me as you have embraced the Traveller. I am its Light when the Light leaves on a new... adventure."
The Guardian was seething; what it spoke must be false! But there was a nagging, niggling sensation in the back of their mind, a quiet voice that agreed with what this... being spoke. If the Traveller existed, there must be a counterpart to its light. But then... why was it here? Why talk to them?
"Would you like to see it?" asked the Eliksni, breaking themy from their contemplation. "Would you like to see my Light, Guardian?"
"I have my Light and I am its protector," came the biting reply.
"And yet there are oh so many of you, aren't there?" it asked. "What good is one Guardian if there are so many others to take their place?" That shook the Guardian and cut deeper than they had expected. It wounded their pride and caused them to lash out in challenge without thinking; to prove their right to be the best and the brightest of the many.
"Then show me your so-called Light. Show it to me so that I may destroy it with Light of the Traveller."
The Eliksni smiled and offered their hand. "Then all I ask for is your Ghost. Only but for a moment." 'That is, after all, all it will take.'
The Guardian was taken aback, their bravado faltering. Their Ghost? It was their only physical link to the Traveller. Without it... they would be lost. But, a challenge declared is a challenge accepted and, with much hesitation, the Guardian brought forth their Shard. It spun in place, looking from one to the other before it was handed over to the Eliksni.
"Thank you, Guardian." A chill crawled down the Guardian's spine as, in horror, they watched their Ghost wither away in his grasp, dying with a final scream as it was overtaken by its Darkness. In an instant, the Guardian's light was snuffed, their connection to the Traveller severed. They were truly alone. "And now, my poor, naive Light, you will see my Light firsthand."