Saitama vs. Tatsumaki

Take it outside!'''

Saitama vs. Tatsumaki is the battle between Saitama and Tatsumaki, the second-highest ranking S-Class hero.

Prelude
In the underground of the Hero Association Headquarters at A-City, after preventing Psykos from being abducted by Apollo, a member of Tsukuyomi, Tatsumaki decides to make Fubuki cut ties with the Blizzard Group. As she is about to punish members of the group in order to make sure that they will not bother Fubuki anymore, Tatsumaki is stopped by Saitama, who jumps in and tightly catches her hand.

Battle
Having been suddenly stopped by Saitama, Tatsumaki is frustrated and tells him to let go of her. When Saitama does not do so and instead asks her to calm down, Tatsumaki tries to send him flying with her telekinesis, although Saitama resists the ability before remarking that her power is not much different from Fubuki's. Provoked, Tatsumaki increases her psychic output in an attempt to get Saitama off her, which blasts through the wall behind him, causing great destruction. Though this don't phases Saitama one bit. However, Tatsumaki is surprised to see that Saitama is withstanding her power, with him simply uttering that his muscles are twitching on their own. She then recognises Saitama as the one who was with Genos whilst Saitama tells Fubuki to escort the others to safety. Fubuki conforms to Saitama's request which prompts the elder sister to ask about their relationship. Saitama replies that he is merely an acquaintance before Tatsumaki proclaims she will find out soon enough if Saitama is worthy of hanging over Fubuki. The surroundings begin twisting due to Tatsumaki's psychic power and in response to this, Saitama tightly grasps her and by forcefully jumping, shoots himself out of the place and heads outside, taking Tatsumaki with him. The two of them crash onto the ground located outside, two kilometers to the northwest from the Hero Association HQ. Tatsumaki tries to get Saitama off her by flinging him around, although to no avail, as he still tightly holds onto her wrist. The female esper blushingly asks Saitama if he likes her, to which he denies, simply saying he does not want her to run away and go around destroying houses again. When Tatsumaki angrily claims that she will not run away from Saitama, whom she considers weaker than herself, he finally lets go of her hand. Complimenting Saitama that he is a little bit strong, Tatsumaki strengthens her psychic output and finger-flicks his forehead, sending him flying backwards, stating that he will not die by just this. Saitama recovers his balance, looks at Tatsumaki, and is excited to see that after levitating a large number of surrounding rubble into the air, she has created a massive tornado out of thin air, the tornado swirling all of those rocks and rubble around. Tatsumaki begins throwing a volley of flying rocks toward Saitama, who, with one arm, deflects one of them away before jumping around the flying rocks in order to evade her onslaught. With the flying rocks missing their target and hitting the ground, they leave sizeable craters each. During this, a family car with three people inside happens to be nearby, on its way to the Hero Association headquarters. Being caught up in the fight, the car is about to be crushed by a boulder, but Saitama intercepts and smashes the boulder, saving the car and loudly telling Tatsumaki to pay attention to her surroundings to avoid collateral damage. Not wanting him to boss her around, Tatsumaki continues her onslaught on Saitama, who with his bare hands, deflects multiple boulders thrown at him but to his surprise, he accidentally diverted a boulder to the direction of the family car. Saitama immediately runs towards the car to protect it but Tatsumaki saves the vehicle first by pulling it into the air, smugly mocking the Caped Baldy and telling him to watch his surroundings, as well.

Tatsumaki lets out a huge psychic wave, destroying Saitama's Niku 🍖 Jacket witch upsets him. He is then blown away to N-City. Meanwhile in the same city the A-Class hero Feather is having trouble with an A-Class Criminal Big Iron and his gang. After learning Erika is not a hostage, Feather stands up ready to fight. Talking about how this would be his climax as a hero! Though this is quickly interrupted as Saitama crashes through the wall, knocking the hero down. Frustrated by the interruption, Big Iron attacks Saitama though he is no match, as Saitama easily punches away the criminal with no effort. While the rest of the gang members are all taken out by Tatsumaki.

Meanwhile, Metal Bat is despatched to H-City to apprehend the dragon level threat Kenzan Rat. Though Metal Bat is in a hurry coming from another city as his cat is about to give birth soon. Metal Bat eventually confronts the rampaging monster after a long distance ran, though before he could even fight the monster is killed by Tatsumaki slamming Saitama through it's head, exploding the brains of the huge beast! Tatsumaki continues to smash Saitama through countless more buildings in their way. Metal Bat looks up at this in frustration about to loose it. He has to calm himself down as he walks home, claiming Zenko is waiting for him.

After Tatsumaki destroys more buildings, Saitama tells her to stop and that they should go back to their original location to avoid causing anymore destruction. She pauses for a minuet and agrees, though as Saitama is figuring out witch way to go next. Tatsumaki slams Saitama's head to the ground and drags him to the bottom of the building their on and down the road while Tatsumaki claims he's looking in the wrong direction and that she'll "help him get there." As Tatsumaki continues to drag Saitama by the head, she notices something chasing after them while commenting on the speed that it could either be a monster or a hero. It's revealed to be Speed-o'-Sound Sonic still attempting to get revenge on Saitama. Sonic throws Homing Exploding Shurikens that he claims are "impossible to escape!" Tatsumaki isn't very interested, telling Sonic to "get lost" as she uses her psychic powers to send the shurikens back at him. Sonic successfully manages to avoid each one but soon slips on dog poo, the shurikens home back in to Sonic and he gets caught up in his own attack cursing Saitama.

Reaching back to the outskirts of the Hero Association headquarters, Saitama slips out of Tatsumaki's grasp, telling her to continue her rampaging.

Trivia

 * In the original webcomic, the fight is interrupted by Tatsumaki's injuries from the Monster Association war, causing both parties to back down. Though in the manga, Tatsumaki passes out near the end of the fight as she pushed herself too far.