WARNING: The following article spoilers for One-Punch Man Chapter 125, by ONE, Yusuke Murata, John Werry, James Gaubatz, available now in English from Viz Media.
After defeating Gyoro-Gyoro, Tatsumaki/Terrible Tornado quickly realized that villain wasn't the true leader of the Monster Association. Instead, a human woman named Psychos -- who is apparently a friend of Fubuki/Blizzard, Tornado's sister -- has been pulling the strings from far underground. Tornado quickly launched an assault on Psycho, and the villain responded by drinking an elixir that enhanced her powers. In One-Punch Man Chapter 125, the battle begins in earnest, with Tornado taking an early lead. However, she might not have it for long.
Tornado pulls Psychos out from the underground with little effort, bringing the villain to fight her face to face. As both are espers, their powerful psychic energy resonates throughout the Monster Association HQ. Tornado easily dominates Psychos and interrogates her about the whereabouts of Tareo, the second kidnapped child, who at that moment is being rescued by King. Tornado soon gets an update from Amai Mask, who she chides for not successfully saving Narinki's mercenaries. The two start arguing, and there's a massive explosion caused by Lord Orochi, who actually survived Saitama's punch earlier in the arc.
Psychos takes advantage of the confusion to throw herself at Lord Orochi. That powerful monster is now a sort of sludge/series of meat chunks looking for blood so as to regenerate. Psychos decides to merge with Orochi so that his "immense form" will be able to give her psychic power a boost.
If Psychos successfully merges with Orochi, she might be able to take Tornado down, as combined the two will be among the strongest on the planet. As Orochi did survive Saitama's punch, he's proven just how formidable he is physically, and combining his might with Psychos' psychic ability could truly make the duo something to fear. Still, while combined they'll potentially be able to take down Tornado without much issue, they'll still have to contend with Saitama. Although he's never really had to go up against a powerful psychic, Saitama has previously triumphed over difficult foes before. And at this time, it seems more like the manga is angling to have him battle Garo, who recently broke through his limiter. As such, don't expect Psychos and Orochi to last long, even if they do beat Tornado.f
The next chapter of One-Punch Man in English releases June 3 from Viz Media.