I Was Reincarnated as a Virus in Another World

A ruthless assassin is killed and reborn as a virus in a fantasy world. With the power to infect and copy abilities from every creature he controls, along with the help of a mysterious system that grants him quests, he begins his ambition to become a shadow ruler. His mission is clear: to conquer this world by spreading an unseen threat. However, heroes and other demon lords start to sense the growing danger. Will they be able to stop the conqueror who continues to evolve in the darkness?