Se'valla (Yup, that's all I got is a name, nothing fancy)
Long ago, when their was nothing, the vast infinity was inhabited by Awin and Asherra, who shaped space and created many different worlds, they also gave birth to several children, who gifted with their powers became God's and Goddess's. Sol & Luna, the twins, Terra, the youngest sister, Ghram & Polis the brothers, Andal the high mage, Janit the Eternal, Nalla and Tanerias, who where slain by the Aberrations. Terra shaped the world, created the flora and fauna,; Sol created Daylight, sky, and it's first inhabitants, the High Elves; Luna created the Night, stars, the worlds waters, and also created her own version of the Elves, the Drow. Ghram gifted these peoples with knowledge of artisanship, music and dance, so they could enjoy their existence. Polis, gave them knowledge of craftsmanship, metallurgy, and fighting, so they could protect themselves. Andal gifted them with the knowledge of Magic, both to heal, and to shape the land around them. From Janit, they were given the breath of life, and longevity.
However, they where not alone, and powerful alien entitles, who had formed on the outskirts of space, outside the watchful eyes of Awin and Asherra. Eventually they attempted to fight them, to steal their divine power for themselves. The aberrations waged a long war against Awin, Asherra, and their children, and would have won if not for the sacrifice of Nalla and Tanerias, who, using their own bodies, imprisoned the most powerful Aberrations into the darkest corners of space, never to be seen again. The weaker, or smarter, ones fled to the planet Se'valla, and many other planets, where they hid from those they had once tried to slay, waiting for the time to strike again.
For many years the God's and Goddess's left the High Elves and Night Elves alone, fighting their own war, and they lived in peace, giving thanks to their creators, shaping the world as they needed, hunting and gathering only what they needed to survive. After a time though, the Elven people where discovered by the Aberrations on Se'valla, and many where twisted by the words their words, and eventually they grew jealous, and prideful, so, in their hubris, attempted to create their own peoples, who would become the Humans. With these humans as slaves, assistants, and whatever else they needed them to be, they taught them Magic, and how to fight. After several generations, with the help of Humans, Elves, and their descendants, the Half-elven children, along with powerful magics taught to them by the Aberrations, attempted to overthrow the Gods. They slew Sol & Luna, and severely wounded Janit, before Plois, Ghram, Andal and Nalla succeeded in crushing the rebellion. Sol became the sun, and Luna became the moon, and thus the cycle of day and night continued without them. Janit's blood spilled across the land, infused with his anger and sadness, it transformed those that it touched.
His blood transformed many of the remaining humans into twisted, hateful and darker versions of themselves, and thus the Vampries where born, and from them, after forcefully, or by tricking Elves, the Dhampir were eventually born. Gaia, who's hatred of her siblings deaths, and the hatred of their creations, unleashed a dark, deplorable, curse on the Elves of those involved in slaying them, and these families became the Tieflings, forever cursed to bear the sin of their ancestors. Several surviving highborn Drow and High Elves gathered their families, and using ancient magics, twisted their form so they could survive in the depths of the ocean, to hide from the wrath of the remaining Gods, although the dark things they found their would twist them even further and eventually they became the Gillmen.
Many centuries have passed since then, and the story of the Gods has faded into myth. Today, the descendants of the Elven people, Half-Elves and Half-Drow, are split into two kingdoms, with many of the Half-Elves living in the Great Southern forest, and the Half-Drow living mostly in the Northern mountain range . The Gillmen, as their called, live mostly in large costal cities, standing both above ground, and deep beneath the water. Tieflings and Dhampir, commonly seen as outcast, are typically nomadic, but some have gotten together and made small cities dotting the western plains, although some larger cities can be found as well.