The last few episodes of Mob Psycho 100 III seemed to have cooled down from the intensity of the Divine Tree arc; however, this was merely a ruse as the dramatic events at the conclusion of episode 9 are developed in episode 10. After being hit by the truck, Mob has been rendered unconscious, and in an all too familiar sequence of events, the raging monster that emerges from deep inside Mob whenever he reaches the mysterious "???%" state is unleashed upon an unsuspecting Seasoning City.
When Mob loses total control of himself, his powers assume a destructive "autopilot" mode that undoubtedly plants him at the top of the list of Mob Psycho 100's most powerful characters. This unfortunate sequence of events in episode 10 yields what is perhaps Mob's most destructive meltdown ever, and this one produces several casualties.
???
Shocked by what has just transpired, everyone involved in the accident, as well as its witnesses idle briefly as the gravity of the situation sets in. The truck driver attempts to call an ambulance, but his phone starts glitching, and various electronic devices across the city are rendered unusable. Before anyone can even react, the ground around the unconscious Mob cracks dramatically as an instantaneous depression forms in the ground around him. The episode cuts to scenes of the situation in the city, with various people complaining about faulty electronics and traffic drawing to a complete halt before an ominous shot of Mob's advancing legs, cloaked in a red aura of what can be described as a visual depiction of pure malice. Every step he takes wreaks unbridled destruction as the ground cracks and shakes and buildings are destroyed, putting countless people in severe danger. He cuts through the forest, holding the flowers in his hand as he advances to his destination when he is intercepted by Teru, for a good reason this time around.
Teru-Teru-Bōsō
Teru tries to talk to Mob, but he quickly realizes what he's up against, having gone up against Mob in his berserk state before. Teru even reminisces on that occasion, since it was the first time he and Mob ever met back during the first season of Mob Psycho 100. Having learned that he is nothing compared to the amazing people who exist out there in the world, Teru's worldview changed since meeting Mob, and he has since tried to push himself to improve himself and see more to himself beyond his psychic powers. He tries to stop Mob because he remembers that the first time they met, Mob entered this "???" state and destroyed Black Vinegar Middle School; however, having regained his composure, Mob ended up crying about what he'd done. On some level, Teru knows that he is outmatched, and Mob's ruthless attacks at his complete, unfettered strength proves to be an insurmountable challenge for him, but he pushes himself to keep up with Mob's assault and continue to get his friend to regain his senses. Throughout the bout, Mob is silent, and the only time he reacts to some kind of stimulus or provocation is when Teru attempts to destroy the bouquet of flowers that Mob got from Minegishi shortly before the accident.
Mob grabs Teru by the throat and flings him quite a huge distance through the forest, and out into a nearby apartment complex, where there are several civilians. Mob advances steadily towards the heavily injured Teru, who continues to stop him before the damage gets any worse; however, the sheer scale of the damage that has been caused ends up making the news and circulating on social media. Serizawa and Mob ignore all evacuation orders, and like most other people, they assumed the incident taking place is just a mere earthquake; however, they soon come across images of what looks like Mob advancing through Seasoning City. With people all around them, Teru finds himself in even greater trouble as he has to protect the countless civilians in the area while maintaining his guard against Mob. Teru tells him that it is relieving, on some level, that even he loses control of his powers sometimes – it makes Mob seem like more of an average person than before, and as his rival, Teru finds that reassuring. Despite his attempts to be brave and get through to his friend, only a glimmer of Mob's consciousness responds to him, unable to break through whatever "this thing" is. Teru is blown away by Mob's might, and the result of this fight serves as a callback to the pair's first ever meeting, which also left Teru naked with a bald patch in his once pristine blonde hair.
Back-Up
During his thorough defeat of Teru, Mob begins to regain consciousness, but remains unable to break through completely. He regains enough sense to be able to understand the gravity of his actions, and that his rampage continues, but he can't control his own body during the "???" state. He continues advancing through the city, eventually coming across former Claw members Megumu Koyama and Yusuke Sakurai, who now work at a Smile Mart convenience store. Sensing the approaching power, the two decide to intercept Mob at the store's entrance, while elsewhere, another group prepares to launch an operation to subdue the rampaging esper. Among them, another familiar face; possibly one of the only people with a sliver of a chance to stop Mob – Toichiro Suzuki, the former founder and leader of the Claw terrorist organization. All while chaos and fear spread through Seasoning City, an unknowing Tsubomi continues to wait for Mob at the park where she and Mob used to play together as kids, wondering if he's really going to arrive. If only she knew.