Magma is a muscular villager from Ishigami Village, counted among its strongest warriors. He possesses blond shoulder-length hair, a prominent jawline, and a heavily built physique. His standard attire includes a dark blue tunic, pants tied at the ankles, leather bracelets, and the village's signature rope belt. Driven by intense ambition to become village chief, Magma plots to eliminate perceived threats. He attempts to kill Gen after mistaking him for Senku and expresses plans to hasten Ruri's death upon gaining leadership. His arrogance and belief in strength as the ultimate solution lead him to advocate violent tactics, like destroying petrified statues to weaken enemies. In the Grand Bout tournament, he employs underhanded methods: ordering ally Mantle to forfeit a match to disqualify Kohaku and attacking Kinro during a distraction. He ultimately loses the tournament, falling for Gen's psychological trick and being defeated by Chrome. A pivotal shift begins during a tungsten-gathering mission with Senku and Chrome. When Senku triggers a cave collapse, Magma pushes him to safety but tumbles into a pit. Trapped together, Senku explains the value of cooperation in science. This reshapes Magma's worldview, compelling him to prioritize saving Senku over his own ambitions. He later declares Senku's inventions "interesting," vowing not to harm him as long as science advances. Post-redemption, Magma actively contributes to the Kingdom of Science. He assists in constructing inventions like cellphones and shock cannons, participates in battles against the Tsukasa Empire, and helps capture Homura. His terminology evolves from labeling technology "sorcery" to calling it "science." Though retaining his impulsive nature and preference for brute force—suggesting they slaughter adversaries on Treasure Island—he increasingly channels his strength toward communal goals. Magma maintains a loyal partnership with Mantle, treating him as an equal despite others perceiving Mantle as a subordinate. His relationship with Gen evolves from hostility to mutual respect; despite Gen repeatedly outmaneuvering him, Magma eventually voices open fondness for Gen and collaborates on tactical plans. He also develops a rivalry with Yo Uei, both competing to prove superiority in tasks like farming and leadership. Following the global conflict's resolution, Magma becomes a police officer under Yo's direction, using his physical prowess to enforce societal order.