Blast is the Hero Association’s Rank 1 hero and, by reputation, the strongest fighter on the planet — though almost nobody has actually seen him in action. He rarely shows up to Association business, treats heroism more like an occasional favor than a job, and is identifiable by the large X-shaped scar across his face and the white-plated combat suit stamped with his name. For most of the cast, he’s less a colleague than a legend other heroes measure themselves against.
What the Association doesn’t know is that Blast’s absences aren’t laziness — he’s been fighting a secret, decades-long war against a god-like entity that’s been quietly corrupting the strongest fighters on Earth, including his own former partner. He surfaces only when a threat crosses into that territory, which is exactly what happens when Saitama and Garou’s fight threatens to tear a hole in the planet.
Blast is a tall, broad-shouldered man in his prime, with spiky salt-and-pepper hair and light stubble. His most striking feature is a large X-shaped scar across his face, centered over the bridge of his nose and his left eye.
Hero Suit
A high-tech armored suit with white plating over reinforced black undersuiting, a chest plate reading "BLAST," a dark visor that hides his eyes in combat, and a flowing white cape.
Flashbacks from fifteen to twenty years ago show a younger, less weathered version of the same suit, with his hair still fully dark.
Stoic, pragmatic, and altruistic, Blast treats heroism almost like a hobby — famously telling others they shouldn’t expect anyone to come save them. He’s driven purely by the survival of all life on Earth, and it shows in how calm he stays even in front of reality-warping threats; he was the first to recognize the danger Saitama and Garou’s clash posed to space-time itself.
His one real weakness is sentiment — specifically, for his former partner, Void. Flashy Flash has called him "too soft" for hesitating to kill Void back when he had the chance, a hesitation that let the villain escape and eventually come back. Blast believes spiritual fortitude is the real key to resisting monsterization, and lately he’s opened up more, coordinating directly with heroes like Flashy Flash and King to prepare for Void’s return.
About twenty years ago, Blast worked as an independent hero alongside a partner named Void, the two of them considered equals in strength. Fifteen years ago, Void accepted power from "God" and monsterized; Blast was forced to fight his own friend, wounding him badly enough to force him into a fifteen-year hibernation. When the professional Hero Association was founded, Blast was placed at the top of the registry, though he’s never bothered following its protocols.
The Subterranean Encounter
Blast appeared deep inside the Monster Association base after Saitama, Flashy Flash, and the monster Manako touched a mysterious cube. He retrieved the cube, noted Manako’s talent, and teleported all three to the surface to keep them out of "God’s" reach.
The Cosmic Calamity
Blast returned to Earth to confront Cosmic Fear Garou, trying to talk him down before briefly clashing with him to keep his nuclear fission attacks from wiping out the atmosphere. When Saitama and Garou’s fight threatened to shatter the Earth, Blast used his dimensional powers to warp the excess energy away.
The Ninja Village Crisis
Blast met with Flashy Flash at Hero Association HQ to explain his and Void’s history and his long mission to keep Void from handing more lives over to "God." During a mission to the "Place of Absurd Dreams," he intervened just as Flashy Flash and Speed-o’-Sound Sonic were being pulled into an illusion by Void and "God," snapping them both back to reality.
Dimension Warp
He can open portals to move himself, others, or massive amounts of energy between dimensions.
Gravity Manipulation / Gravity Knuckles
Control over gravitational force, which he can concentrate into his fists for devastating blows.
Higher-Dimensional Perception
He can perceive and move through higher dimensions, letting him attack from angles a normal three-dimensional being can’t comprehend.
Superhuman Speed
Fast enough to appear behind Flashy Flash instantly during a reflex test — faster than the ninja himself.
Space-Time Awareness
He can sense shifts in the space-time continuum and detect when a gate to a higher dimension is opening.
vs. Void — 15 Years Ago
Fought his own monsterized partner to stop his rampage. Wounded him badly enough to force a 15-year hibernation, but couldn't finish it — the fight that set Blast's whole mission in motion.
vs. Cosmic Fear Garou — Ch. 164–165
Tried to contain Garou's nuclear and gravitational attacks before they could tear apart the atmosphere. Held the line long enough for Saitama to take over — proof Blast is one of the few beings on Earth who can even stand against a "God-powered" threat.
vs. Flashy Flash (Test) — Ch. 194
Flash tried to test him with a high-speed kick. Blast dodged it and was already standing behind him before the kick even finished — the gap between Rank 1 and the rest of the S-Class, reaffirmed in one moment.
Major: Ch. 138, 139, 140, 164, 165, 166, 194, 195, 196, 202.
Minor: Ch. 124, 161, 162, 167, 168, 169, 170.
Mentioned only: Ch. 32, 111, 127, 128, 129, 186, 280.
Void (The Great One)
His former partner and current nemesis. Blast feels personally responsible for Void’s fall and is still torn between wanting to save him and needing to end the threat he poses.
Saitama
Blast is intensely interested in Saitama’s power, which he considers impossible to fully measure.
Tatsumaki
Years ago, Blast rescued a young Tatsumaki from the research facility where she was being held, and his parting words to her — "those who possess great power must never expect someone to save them" — went on to define the rest of her life.
Flashy Flash
Blast respects Flash’s skill but calls out his tactical impatience; the two work together investigating the Ninja Village’s remnants.
Blue
A young man explicitly identified as Blast’s son.
Sitch
One of the few Hero Association executives Blast communicates with directly.
"God"
His central antagonist — the entity he’s spent two decades holding back from infiltrating the human world.
“No... I suspect we will meet again.” — to Saitama
“Is that what you really want?! That your divine power threatens the survival of all life on Earth?” — to Garou
“I’m Blast, an individual acting as a hero.”
“Those who possess great power must never expect someone to save them.”
Unlike most S-Class heroes, Blast hates public attention, and his identity is kept secret even within the Hero Association’s own registry. He’s the only hero explicitly stated to operate purely as a volunteer, with no obligation to Association restrictions. He’s also the only known character to collect the mysterious "Cubes" and hand them off to his own team of interdimensional collaborators for study rather than use them himself.