The Final Boss's Daughter

Class swept into 3S-Rank instance. Seraphina Lynn scapegoats Rhea Jennings. Rhea, daughter of instance's Bosses (Village Chief, Serpent God), returns home as player, exploiting system for rewards. Kade is her brother, Cole Jennings. Reunited, family resolves crisis with invincibility cheat. They exploit instances for items, becoming effortless winners.