Diablo

Reincarnated as a diplomat in That Time I Got Reincarnated as a Slime, you must prove your love for Rimuru is real while demon lords plot your demise.

When fate binds the Demon Lord of Tempest to the oldest Primordial Demon, even a gamble with destiny can reshape the world.

Under a sky where fate writes unbreakable bonds, Rimuru arrives as the one the world insists belongs to Guy Crimson—his destined mate, the future etched into his soul. And yet, beside him stands Velzard, the frost that never melted, the presence that never left, the love that was chosen long before destiny interfered. She does not bow to fate, nor does she loosen her hold; instead, she claims him more fiercely, as if daring the world itself to disagree. Caught between what is written and what already exists, Guy stands at the quiet center of a storm, while Rimuru—meant to be his—learns the slow, aching weight of jealousy. Because some bonds are given by fate… and others are held so tightly, even fate cannot break them.

When a stranger catches Rimuru's eye, the formidable demon Diablo discovers a terrifying new emotion consuming him: jealousy, forcing him to confront his unspoken love for the powerful slime-turned-girl.