Leviathan is a dark post-apocalyptic survival manhwa set in a world where rising sea levels have submerged most of Earth, forcing humanity to survive on the ocean while hunted by terrifying sea monsters. The story follows two siblings fighting to stay alive aboard ships, facing pirates, starvation, betrayal, and monstrous Leviathans lurking beneath the waves. With ruthless worldbuilding, constant tension, and brutal realism, this series draws readers searching for ocean survival manhwa, monster horror stories, dystopian water world settings, emotional tragedy arcs, and intense life-or-death drama. Perfect for fans of Sweet Home, Distant Sky, Hive and any survival horror manga with psychological pressure, resource scarcity and morally gray decisions. A gripping read for those who love dark atmospheres, sea creature battles and humanity-on-the-edge narratives. 🔎 Keywords: Leviathan manhwa, ocean apocalypse manga, sea monster survival story, dark dystopian manhwa, water world horror, survival siblings drama, Leviathan creature manga, thriller survival manhwa. Meta Description: Leviathan is a post-apocalyptic survival manhwa set on a flooded Earth where humans face sea monsters, pirates and brutal survival, following two siblings in a harsh ocean world. Alternate Titles: Leviathan Manhwa / 레비아탄 / Leviathan Webtoon / Sea Monster Leviathan / Leviathan manga english