Wandering in Omniverse

Jason was the top assassin back on earth but during a dangerous life-threatening mission, his life came to an end. But fate has something else in store for him as he encounters a goddess who sends him on a thrilling adventure through the omniverse. From futuristic worlds to medieval realms, and even the anime universe... there is no place far from his reach. Now follow along his journey as he travels through different universes to uncover the secret behind his own existence. But can he really get the answers to his questions, or will he... — Description from novelcodex.org