The World's Finest Assassin Gets Reincarnated in Another World as an Aristocrat, Vol. 1 (light novel)

When a great assassin is reborn in another world, he finds himself the heirto a long line of killers from the shadows. With both his modern-day knowledgeand experience and the special magic and techniques of this new world, he couldvery well become the most unstoppable assassin in history...!