In a world where individuals possess a maximum of eight innate skill slots, the protagonist, a slave in an ore mine, witnesses the death of his master during a cave-in. This event breaks the magical contract binding the slaves, allowing them to acquire skills. While others seize rare skills and escape, the protagonist finds an extraordinary skill orb: World Ruler, which requires ten slots. He is able to use it because he is a reincarnator with sixteen slots. Now surrounded and with only one escape route, he must use his newfound power to survive.