Chapter 166 (Online): Squared

Armed with borrowed divine strength, Garou lays waste to the heroes gathered around him. Blast steps out of a portal to talk the Hero Hunter down, but the fight has already turned lethal by the time Saitama comes back. Genos and most of the assembled fighters lie dead, leaving Blast the last one on his feet.

Sick with grief and blaming himself for showing up too late, Saitama drives a Serious Punch straight at Garou. The monster meets it with a punch of equal force, and Blast, reading the raw energy stored in both fists, realizes the collision could threaten every living thing on the planet.

Child Emperor and Waganma bleed from the nose and pass out, and Zombieman notices hair sloughing off the young hero's head as he and Sekingar rush over. Bang orders his former pupil to come back to his senses, insisting something evil has taken root in him, but Garou claims he acts freely. Blast then arrives and warns Garou that God is pulling his strings, adding that any attack could wipe out life on Earth.

Nearly every hero drops from the cosmic radiation pouring off Garou, who laughs and crowns himself the Ominous Future, a Disaster Level of God. Manako tries to slip away, collapses, and glimpses the unconscious Tareo before she fades. Genos then throws himself at Garou with his last reserves. Blast counters with Dimension Cannon and Gravity Knuckle, chaining portals together to trap Garou in a pocket dimension.

Garou absorbs the portal technique, breaks free, and hits back with Nuclear Fission: Gravity Knuckle, which Blast redirects skyward. Dismissing Blast because he knows Saitama will return, Garou grabs the helpless Genos and drives a hand through his chest. Saitama reappears under a fall of black rain, catches the depleted core Garou hurls at him, and unleashes his Serious Punch, which Garou answers with the same blow through Mode: Saitama.

The cover art paints the Horsehead Nebula, an equine-shaped cloud from the constellation Orion, across Garou's body. The installment belongs to the Monster Association Arc and adapts portions of webcomic chapters 77 and 82. It released online on June 23, 2022, under the online title Squared, localized by Viz Media as Power Squared.