Miles Carter was betrayed by his close friend Anthony Grant and his girlfriend Megan Caldwell. After falling into the river, he was unexpectedly reborn as a crayfish and awakened the Devour‑Evolution System. He fled and survived, growing stronger through countless trials, and successfully took revenge on his enemies. Later, he discovered that his original body was being illegally used by forces from the Beacon Nation, so he fought powerful foes—including beasts and mechanical forces—gradually evolving into a divine dragon. He befriended divine beasts of the Eastern Sea, protected the sea region, settled all grudges, and finally returned to human life.
