Within the span of a few short hours, a cosmic phenomenon had everyone mesmerized. Across the world, people were transfixed by the expansive green trails that had taken over the sky. Reports emerged of an extraordinary sight for those who gazed upon them at night: a radiant interplay between the shimmering streaks and the twinkle of the stars, casting a mesmerizing sheen on their undulating movements.

The trails descended from the sky in no time, growing increasingly vivid and majestic with each passing moment until they touched the ground in a thick, green, iridescent fog. Visibility in the city streets dropped dramatically, and people began to inhale the dense dust without realizing it. Terrifying screams soon followed, causing widespread panic as some ran aimlessly, hoping to escape the fog's grip. Meanwhile, everyone else had already begun the metamorphosis.

The bones were compressed and twisted, causing them to shatter under the pressure of the growing muscles. Hideous scales and filaments erupted from the skin, causing deep wounds and lacerations. Victims suffered a brief, agonizing transformation that lasted only minutes, as their brains were hijacked by an unknown force. When the metamorphosis was complete, a grotesque new creature emerged, utterly unlike anything humanity had ever seen.

With their agility and strength, the deadly beings known as devourers proved to be tragically lethal. As they emerged from the green fog, they preyed upon the disoriented humans who stumbled their way out of the mist. Those who were unable to undergo the transformation were ripped apart and consumed by the insatiable creatures, whose craving for human blood knew no bounds. The horrifying scene played out in every corner of the world. And as the sun rose on a new day, the abominations created by the green fog prowled the streets, searching for any survivors to feed upon.

It was the solitaries, the hermits, and the ones who shunned society that had the best chance at survival. Most of them transformed, becoming crazed and lost, and hunting for prey that was too far out of reach. Others only experienced partial transformation, and while their bodies began to show signs of the disease, they maintained their sanity. Fighting for their lives, they banded together with other survivors, building a new society over time. Their children were born into a world of horror, but they learned to become expert hunters, skilled in the art of killing the devourers, and eventually, they inherited the world.

Half a century after their ancestors perished, the descendants of humankind uncovered a profound link between their blood and the dark liquid coursing through the veins of the devourers. They dubbed it Ichor, the divine blood, and found that injecting a compound of blood mixed with a precise amount of this substance could reignite the metamorphosis process. The goal of the transmutation was to elevate the individual's physical transformation without compromising the brain. Those who survived the practice emerged invigorated and displayed remarkable physical prowess.

As time went by, transmutation became the means to rule the world. Blood and Ichor were the last remaining valuable resources on Earth and sparked gruesome conflicts and massacres. Meanwhile, the devourers began to morph into new, exceptionally unique shapes. Some argued that these creatures still harbored a shard of their former humanity, which eventually resurfaced and drove their new transformation.

Nowadays, the heirs of humankind - the slayers - fight for dominance over the ruins of the once-great cities and the limited supply of blood. And as they search for meaning in the ashes of their past, something sinister stirs from the dark abyss of the Earth.