I, an Alien, Saved the Vampire Queen at the Beginning

Novas, an absolutely strong man from a distant planet, pursues the secret of immortality and wanders alone in the universe. He accidentally landed on Earth and accidentally saved the blood queen Liesel who was besieged by human heroes and was on the verge of death. The once invincible queen was now so weak that she had to rely on the protection of Novas in order to survive. Protagonist boss