Deep within the ruins of an ancient civilization, a legendary alchemist awakens. Vaiken Ordo has succeeded in a dangerous reincarnation experiment, cheating death to be reborn in the body of a young boy. However, his triumphant return to the world is met with an unexpected reality: five hundred years have passed, and the art of alchemy has been entirely forgotten, rendered obsolete by the rise of a new era of magic.

Determined to uncover what transpired over the centuries and to restore his craft to its former glory, Vaiken begins a new life as both an adventurer and an alchemist. Working out of his old, dilapidated laboratory, he is accompanied by a clumsy, artificial fairy companion. Despite his youthful appearance, Vaiken possesses the immense knowledge and power of a master alchemist from a bygone age. His abilities quickly set him apart in a world that no longer understands his methods, allowing him to achieve feats that seem miraculous to the modern populace.

Vaiken's actions soon draw the attention of powerful forces. The royal capital, intrigued and threatened by his unexplainable power, attempts to bring him under their control. Vaiken effortlessly rejects their demands, demonstrating the overwhelming gap in ability between himself and the current era's mages and knights. However, this defiance results in him being persistently pursued by a peculiar and eccentric female knight named Maia.

While dealing with political intrigue and his unwanted admirer, Vaiken encounters a mysterious and unknown monster called a Malignant. After defeating the creature, he discovers a disturbing connection: these beasts are linked to the downfall of the dynasty that ruled five hundred years ago, the very same cataclysm that led to the decline of alchemy. His investigation puts him in the crosshairs of a sinister man who smiles ominously as he targets the reborn alchemist.

As Vaiken delves deeper into the mystery of the world's decay, he learns that the key to the present crisis lies in the truth of the past. His journey to revive alchemy becomes a battle to prevent a second apocalypse. Ultimately, Vaiken must confront an ancient sage in a final, decisive battle to protect the future of humanity, using his unparalleled mastery of alchemy to save a world that had forgotten him.