Karin Sasaki serves as a Third Generation pyrokinetic in Special Fire Force Company 4. His pyrokinetic power, Scale Shield, manifests as defensive hexagonal flame barriers. These shields safeguard individuals from attacks or falling debris and can expand into larger protective structures like semi-domes covering coastlines, especially when amplified by Pan Ko Paat's support in techniques such as Scale Shield: Full Force Deployment. He possesses narrow lizard-like pupils and multicolored hair, predominantly black with sharp red bangs. On missions, he typically wears the standard orange Special Fire Force jumpsuit or bunker gear. Initially arrogant and rude, Karin antagonized Shinra Kusakabe due to rumors about Shinra's family. However, he strictly upholds Company 4's motto: "Never leave a man behind and protect the survivors." This principle drives him to prioritize team cohesion and protect allies, even those he personally dislikes, revealing an underlying loyalty. During training exercises, he clashed with Shinra but was quickly overpowered. Later, in the VS. Company 4 arc, Haumea mentally controlled him to attack Shinra, an incident he retained no memory of afterward. He participated in defending civilians during the Stone Pillars arc, notably aiding against the Titan Infernal at Tama Bay. Though objecting to assisting the criminalized Company 8, he complied with orders to support them. In the Final Pillar arc, he fought alongside Company 2 and Haijima agents against mass-infernalization and Raffles I's assault, deploying his shields to protect civilians during coastline battles. Karin perished during the Great Cataclysm but was revived when Shinra Kusakabe rewrote reality. His surname "Sasaki" means "help, aid" (佐) and "tree, wood" (木), while "Karin" (火鱗) combines "fire, flame" (火) and "scale" (鱗), reflecting his pyrokinetic motif.