Strange Tales of Rules: Taking Care of Roommate's Girlfriend at the Beginning - Chapter 71 – Last chance for a reminder! Is someone singing?

Reiji Saeki, who lives in the north eastern countryside town, lost his life in an accident during summer vacation. ……But before he knew it, a mysterious ball of light hovered in front of his eyes in a world of whiteness. That ball of light was a magician from a parallel world, and is looking for a person qualified to inherit the magic they had created to prevent it from being lost. Reiji, who rode on that suggestion, now lives in the parallel world Elgin, with a new body and powerful magical power.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

A sudden and unprecedented event occurred and took place on Earth.A fissure instantly appeared in the clear blue sky, revealing a void devoid of any light beyond, instantly covering the whole planet, leaving no Life, no Hell, and no Paradise behind...Hence the start of a new chaos and a great beginning of life devoid of any hope began.In this apocalypse and lawless world without any limits set upon its beings, a silent dark wisp took form.A wisp that was bound to become the Horror of All was born...“Wait… I’ve become a Ghost?!”

System: You are the only human who meets the binding requirements of this system, please bind with me!