Saitama rarely takes anything seriously, but when he does, his techniques unleash unparalleled destructive power.
In the world of One Punch Man, when Saitama switches to serious mode, hardly any opponent stands a chance against the Bald Cape. And up until now, Sai has revealed 5 techniques in his serious arsenal:
1. Serious Punch - The Punch of Seriousness

Saitama's Serious Punch possesses extraordinary destructive force. For instance, when Elder Centipede took the full brunt of Saitama's Serious Punch, the Dragon-level monster was instantly 'exiled from Earth.'
Recently, when both Garou and Saitama engaged in a serious punch collision, its sheer power could have annihilated the Earth if Blast hadn't intervened in time. Despite cleverly relocating Sai and Garou off Earth, the energy output from the clash of the two punches was so immense that even Blast's gate couldn't handle such a massive energy surge.
2. Intense Lateral Leap - Serious Sidestep

Saitama employed this technique against Sonic, aiming to end the battle swiftly. Executing it, Saitama swiftly jumps from side to side, creating a residual image wall. The shock waves from the residual image induce Sonic into supersonic unconsciousness.
3. Serious Soaker - Gravity-Aided Water Cannon

This technique emerged in Saitama's clash with Orochi deep underground. To unleash it, Saitama harnesses the magma around him and sprays it at his foes. Employing this move while submerged in sludge, Saitama fully neutralizes Orochi's Gaia Cannon, a tremendously potent attack drawing energy from Earth's core.
4. All-Direction Serious Strike - Multi-Vector Punch

This technique appears as a fusion of his first two techniques. Saitama starts by swiftly moving from various angles to create multiple residual images and assaults Garou with Serious Punches from various directions simultaneously. Confronted with this move, Sai's adversary finds it extremely challenging to evade. Despite Garou's belief that he's dodged all the punches through his created portals, he ultimately gets hit as Saitama relentlessly pursues him even within the portals.
5. Gravity-Defying Table Flip

Saitama's latest technique, the Gravity-Defying Table Flip, shattered the entire lunar surface of the Moon. It left Garou feeling completely disoriented, akin to a bug trapped in a child's playpen.
During the execution of the Gravity-Defying Table Flip, Saitama pressed his finger into the ground and exerted all his strength to lift it. As seen in the image above, a massive shockwave lifted the entire surface of the lunar Moon into the air.