Demon Slayer: I Have an Arsenal

Su Ran was watching an anime he loved when a single snarky remark sent him to a time that felt utterly unfamiliar to him.

In this world, more unfamiliar to Su Ran than anything he could imagine, he used the System to build his own legend.

Muzan Kibutsuji: How can my Upper Moons be this weak?

Kokushibo: Lord Muzan! It's not that we're slacking. It's just that... times have changed!