Eiran doesn't remember his childhood, as, like all remnants, he never had one. The gods that create them usually abandon them upon seeing how they would look and act as adults, so when he entered the Void, he simply appeared at the edge of the world, fully formed and fully grown, hidden in the only patch of darkness he could find. When he was eventually discovered by a group of void runners, they were baffled for a while as to how to remove him - he was found deep within the arctic wastes of the god of light’s realm, yet his extreme light sensitivity meant that all he could do was curl up under a thick slab of ice and snow with his eyes covered. At the time, Remnants of the god of darkness were unable to travel outside of their neighborhood due to their sensitivity to light, so it was assumed that he was a darkness remnant that had just gotten mixed up into the light realm somehow. Eventually, the void runners managed to heavily bundle his eyes with some spare clothing they had and carried him to the city of Praecidia, where he would be settled into his future home.
However, settling was not easy. When word got out that a darkness remnant had been found in a piece of the god of light’s failed creation, he had been hailed as a savior by the more pious remnants, who believed he held the key to traveling between realms, which would allow them to leave the Void and rejoin their gods in their paradises. As a result, he was catapulted into fame for a while, his natural friendliness only further encouraging the sudden hordes of fans he was forced to contend with. While he was empathetic to their plight, and wanted to help, the fact remained that Eiran had no idea how he had been born into a different region, and no amount of theorizing could satisfy the remnants that idolized him and demanded concrete answers. It grew so bad that he could no longer handle the pressure and the fear of not living up to their expectations, and so he shut himself away, living as a recluse until the other remnants eventually lost interest.
He spent months alone in his home, living off of a meager stockpile of food and books supplied by the void runners who had taken him to Praecidia, but boredom eventually settled in, and after a while he had had enough. When he finally stepped outside again, most of his fans had lost interest and dispersed, but the incident still colored his view of the pious remnants from then on. He had decided during his long, self-imposed confinement that he would not follow their example: regardless of what the gods thought of him, he had been put in the void, and that was where he would focus his attention, not on beseeching a higher power to take him away from the world he lived in. While he couldn’t leave his neighborhood, for the endless night of Praecidia Noctum was the only place that didn’t burn his sensitive eyes, he traveled around it extensively, looking around and trying to figure out what his purpose should be, what niche in the world he could fill.
During his travels, he became familiar with his neighborhood and the people in it, meeting remnants of all races, colors, and ages. So too did he meet those less fortunate than he, ones who had been created with defects, or had gotten injured before the void runners had found them, or who were sickly, each day of their lives in the Void a constant uphill struggle. No treatment for them existed, not from the gods nor from the other remnants, try as they might, and it was with them that he found his purpose. Someone had to help them, and he turned to a volatile, detail-oriented science to do it: alchemy. A strange science, alchemy within the Void is a blend of traditional chemistry and the art of creating objects from reagents, materials imbued with magical energy. Those who craft an unstable concoction can find themselves dealing with explosions, poisons, or tears in the very fabric of reality. Those who master it, however, were said to be able to craft miracles, and a miracle seemed to fit what Eiran was looking for. He started small, mixing chemicals and existing medicines to try and strengthen them, often experimenting on himself to test the effects. When he had come up with something worthy of being traded for, he brought them out and handed the samples out for free, unafraid to push his former fame as a savior of the pious to convince others to try it.
Just as he had hoped, they worked. He soon found himself dealing with a modest, but steady demand for what he made. Soon, his medicines grew more ambitious, his skills grew, and he began to tackle the dangerous world of artificing, crafting prosthetics and simple tools to assist disabled remnants. Always, however, he remembered where he came from - no matter what, Eiran refused payment for what he did, instead trading his creations for a meal, more materials, or even just a bit of companionship before he had to run off and fill another order. He started to make a name for himself among the remnants of Praecidia Noctum, and his continued experiments despite this led to what would become his greatest breakthrough yet.
One evening, while working with samples of glass, Eiran noticed that one of the glass shards he had been working with had turned a strange color, a deep, rich brown that was nearly opaque, it was so dark. It sparked in him a wild, crazy idea, and soon he was out on the streets again, seeking out a tourist shop and their brightest candles, used only by the foreign remnants who felt the need to venture into this neighborhood of eternal night. With shaking hands, he crafted a eyepatch-like rigging for the glass, slipped it on, and lit the candle, looking directly into the brilliant light the flame gave off...and it didn't burn. He could see the flame, see the light it gave off, but it was dim, just dim enough that he could look at it comfortably for as long as he wanted.
While the candle burned down into a pool of wax, Eiran was hard at work, recreating the solution he had left the glass to soak in and petitioning the greatest artificer he knew to craft a light-blocking harness to hold it. Many weeks later, after countless tests and experiments, Eiran stood at the edge of his neighborhood, strapped on a strange, bulky visor...and walked out of Praecidia Noctum into the world beyond. Others soon followed, a select few who had volunteered for this final great experiment and had had visors of their own made, who looked upon the homes and business of their neighbors, lit by a once-blinding sun, and were struck by exactly what the alchemist had done for them. The remnants of the god of darkness, trapped for so long in their neighborhood of eternal night, were finally free, their sensitivity to light no longer a crippling burden.
Eiran traveled north, his friends and volunteers behind him, to the head office of the void runners that lay deep within Praecidia Luxor, the longtime home of the remnants aligned with the god of light. They stood without pain or fear at the front desk, lit by the everburning Luxor sun, and together proved their identities as darkness remnants, presented this new breakthrough, and introduced the man responsible for it. Eiran was immediately brought to the leaders of the void runners, where he presented the exact recipe and blueprints for his visor, the benefits it brought to every Praecidian citizen, and his terms, which were simple and kept to the philosophy he'd established for his work from the very beginning - the visors could only be sold at their cost, and for the residents of Praecidia Noctum, they would be free.
The void runners didn't need any further convincing, with the evidence right in front of them. Soon, Eiran's visors were produced on a massive scale, and for the first time, remnants of the god of darkness could explore the rest of the city, living, working, and thriving away from their original homes. The void runners gained a massive influx of new members aligned to darkness, and for the first time since the city's founding, teams of void runners had members from all seven elements, each on equal standing, each an expert in their field. Eiran, meanwhile, could never sit and be a hero for long. He soon returned home and moved on to his next project, taking commissions from his clients and continuing his experiments in his spare time. While he's not sure what exactly he intends on making next, he's content with just helping whoever he can, glad to have found his place in the world and the freedom to travel around outside of it if he so chose.