A Fisherman, but He Fishes Through the Heavens

He was once a Shura from all realms who slaughtered the heavens, but now he just wants to be a fisherman betting against the heavens. Until he swung the rod out, what he caught was not a fish, but a young man from outside the world. He also caught the gaze of the high-dimensional "fisherman" and the pursuit of the entire world. When the truth of the universe is a cold "fish tank", he chooses to burn everything to anchor the last real warmth in nothingness for the people he cares about.