Gestronio

In the year 2200, Earth is protected by ALKEN, an elite organization that investigates cosmic threats before they reach humanity. When commander Londo Martino discovers a distant planet called Gestronio, he makes a decision that will change history. Despite political opposition and the fact that its inhabitants show no hostility, Londo launches an antimatter weapon powerful enough to erase the entire world. The planet is destroyed. But something survives. After secretly reaching Earth, the last organism of Gestronio takes control of the body of an ALKEN agent named Steven Yokogjo. Wearing a human face, the creature begins a quiet war against the species that annihilated its world. By night, it kills. By day, it lives among humans as Steven. As suspicion grows inside ALKEN, an unexpected bond with a fellow agent named Anna begins to challenge the creature’s desire for revenge. Because for the first time since the destruction of its world, the last survivor of Gestronio may begin to understand the very people it swore to destroy.

Aliens Fighting Humor Leading Ladies Mature Murder Adults (18+)
ecchi love manga space opera violence