Virus Tensei kara Isekai Kansen Monogatari

Death was supposed to be the end, but instead, it marked the beginning of a bizarre new existence. Upon regaining consciousness, the protagonist discovers they have been reincarnated into a strange and unfamiliar fantasy world. However, rather than being reborn as a hero or even an ordinary creature, they find themselves inhabiting the body of a rat. The truth is far more unsettling: they have not simply become an animal, but rather a sentient virus that has completely infested a rodent host. This unprecedented form comes with a terrifying advantage. As a pathogen in a new world, their power lies entirely in contagion. Every successful infection grants them access to additional bodies and allows them to assimilate new skills from their hosts. What begins as a single compromised rat quickly becomes the foundation for exponential growth, turning every living creature encountered into a potential vessel and a source of newfound strength. Armed with this unique ability to multiply and evolve through transmission, the protagonist sets a singular, ambitious goal. Instead of seeking a quiet life in this other world, they intend to unleash an unstoppable pandemic. By spreading relentlessly across the land, they will build an ever-expanding network of infected hosts, transforming an entire realm through the sheer force of viral conquest.