Invasion of the Calamities

[Urban supernatural powers + cold-blooded assassin + reborn + one heroine + no romance]

...By the hand of fate, two people with tragic pasts cross paths: a profoundly cold-blooded assassin, reborn, and an extraordinarily optimistic girl.

...When his supernatural powers awaken, he gains a conscious attendant with an impressively versatile set of abilities, like a cheat code. But its personality is completely different from his own?

...In Star Era 1051, rifts heralding disaster appear. The world falls into turmoil, natural calamities strike one after another, and disasters engulf the entire planet.

...Humanity's conventional weapons are almost useless against these alien creatures. Researchers have named them Otherworldly Beasts.

The rifts are expanding, and the apocalypse is drawing near.

Humanity wages a long war of attrition against the Otherworldly Beasts, and the creatures emerging from the rifts grow ever stronger.

Will human civilization be destroyed? What will it take to bring this to an end?