The story begins with the tragic sinking of a ferry carrying students from Yasaka Prefectural High School during a school trip, caused by a terrorist bomb. Among the 102 passengers and crew who died was Amamiya Hiroto, a student who sacrificed himself to save his classmate Naruse Narumi, the class's mood-maker. In the afterlife, Hiroto learns that his death was not in vain, as he and other deceased souls are offered a chance at reincarnation in a different world with special powers by a divine being named Rodocorte.
Hiroto, who had a difficult life with deceased parents and strained relations with his uncle's family, readily accepts the offer, hoping for a happier second life. However, a clerical error by Rodocorte leads to Hiroto's name being mistaken for another student with a similar name, Amamiya Hiroto. Consequently, Hiroto receives no special powers, fate, or luck, and is instead cursed with a "negative start," meaning he will face even greater hardship than before. Despite his protests, he is sent to the new world, "Origin," with only a vast amount of latent magical power but no aptitude for magic itself, making it a "treasure to be wasted."
In Origin, Hiroto is reborn as Vandalu, a half-dark elf, half-vampire (Damphir) in a military nation. His life is marked by extreme hardship, including being sold by his mother and subjected to cruel human experimentation by a research institute. They discover his immense magical power and the eighth attribute, "Death," which he masters. After enduring years of torture and manipulation, Vandalu dies during an experiment. He is then re-reincarnated by Rodocorte, this time with the intention of him being a "practice run" for a larger plan.
Vandalu's second life in Origin is a brutal cycle of abuse and experimentation, culminating in his death at the hands of his former classmates, including Narumi, who have become powerful "Hundred Heroes." Driven by hatred, Vandalu's soul is sent back to Rodocorte, who explains his plan to reincarnate 100 individuals with special abilities into a world called "Lambda" to foster its development. Rodocorte, seeking to rectify his mistake with Vandalu, offers him a third chance at life in Lambda, but without any powers or luck, and with a curse that prevents him from gaining experience or jobs.
Reborn as Vandalu in Lambda, he is raised by his mother, Dalsia, a dark elf, and develops an immense magical power but no aptitude for conventional magic. He also acquires the "Death Attribute Magic" and the ability to create and control undead. After his mother is unjustly killed by the local authorities and adventurers, Vandalu, fueled by grief and a thirst for revenge, embarks on a path of destruction. He uses his undead minions to systematically eliminate those responsible for his mother's death and the town of Ebujia, which had wronged them.
Vandalu's journey in Lambda is characterized by his struggle to survive and grow stronger despite Rodocorte's curses. He learns to utilize his unique abilities, including his immense magical power and control over undead, to overcome challenges and protect his mother's spirit, which resides in a bone fragment. He also discovers the world's history, its gods, races, and the complex political landscape, all while honing his skills and gathering allies, including his undead creations. His path is fraught with danger, prejudice against his mixed heritage, and the constant threat of powerful enemies, including other reincarnated individuals from his past lives.
