Episode 29

"Hero Killer: Stain vs. U.A. Students" is the twenty-ninth episode of the My Hero Academia anime and the sixteenth episode of Season 2.

Summary
Izuku exits the train and starts running towards Hosu to help Gran Torino against the Nomu.

Gran Torino had smashed the Nomu into a small building. The Nomu slashes at Gran Torino but the elderly Hero jumps out of the way in time, dodging its attack. Gran Torino sees that the Nomu is about to attack two civilians. Gran Torino jumps at the Nomu in order to save the civilians. However, the Nomu is scorched by flames, forcing Gran Torino to stop his attack and back away. Endeavor, the hero who scorched the creature, says that he hasn't made acquaintances with the elderly hero, telling Gran Torino that he will deal with the Nomu because he is a Hero Izuku has arrived in Hosu and witnesses a battle between the Pro Heroes and two Nomus. Izuku is surprised that Tenya isn't at the battle and starts pondering. Izuku quickly figures out that Tenya came to Hosu to find and hunt down Hero Killer Stain. Izuku leaves the battlefield and searches for Tenya.

On top of a building, Tomura praises the three Nomus for their destruction. Kurogiri asks Tomura if he will join the attack, however, Tomura replies that he won't because he is injured.

The battle between Tenya and Stain begins; Tenya attacks Stain with a high speed kick, but the Hero Killer dodges Tenya's fast kick with ease by jumping above him. Stain kicks Tenya's right arm, causing it to bleed and slams Tenya onto the ground with his left foot. Stain stabs Tenya's left shoulder with his katana which defeats Tenya. Stain reveals to Tenya that he let Tensei live in order to feed rumors. Stain says that both him and his brother are weak because they are fake heroes. Tenya, even though he is defeated, rebukes Stain's claim that his older brother Tensei is weak, yelling that Tensei was a splendid Hero and that he will kill Stain to avenge his older brother. Stain tells Tenya to save the injured pro hero behind him, surprising Tenya. Stain preaches to Tenya that he must act selflessly by rescuing others first and not be selfish by brandishing his power for his own sake. Stain states that seeking revenge just to satisfy one's selfish desires is the act furthest from the title of "hero" which is why he will die now. Stain stomps his foot on Tenya's head and prepares to kill Tenya with his katana, saying that Tenya will be an offering to a just world. Tenya refuses to listen to Stain's preaching, yelling that Stain is just criminal scum who hurt his older brother.

Stain is about to deliver the finishing blow. However, Izuku suddenly appears, having activated One For All Full Cowl throughout his body and punches Stain in the face with his enhanced might, preventing the Hero Killer from finishing off Tenya. Izuku announces his arrival and declares that he came to save Tenya.

Izuku asks Tenya if he can move, but Tenya tells Izuku that he is immobilized. Stain praises Izuku for his efforts and threatens Izuku that he will kill Tenya if he gets in the way, asking the young Hero what he will do. Izuku plans on what to do; two people are injured and require protection. Izuku decides that he must protect Tenya and the Pro Hero by trying to drive Stain away; Izuku sends a message to someone using his phone. Tenya orders Izuku not to get involved since his fight with Stain has nothing to do with him. Izuku responds to Tenya's order, saying that Heroes would not be able to do anything by following Tenya's logic. Izuku puts on a brave face and says that getting involved in other people's business is one of the principal qualities of a Hero; Stain smiles at Izuku's statement.

Izuku and Stain begin their battle; Izuku activates One for All Full Cowl throughout his body and Stain charges at the young Hero. Izuku manages to get close to Stain and runs through the gap between Stain's legs, avoiding the Hero Killer's katana and dagger slash. Stain counters by slashing at Izuku with his katana, but Izuku dodges by jumping into the air and above him. Izuku, above the Hero Killer, uses 5% Detroit Smash on Stain, delivering a powerful blow to Stain's head. Tenya is shocked at Izuku's fast movements, comparing them to Katsuki's movements. Stain, unfazed by Izuku's move, licks his dagger and activates his Quirk; Izuku becomes immobilized and unable to move. Izuku wonders why Stain's Quirk is working as he never managed to cut him. Izuku realizes that it is blood that allows Stain to activate his Quirk.

Stain, impressed with Izuku's actions, decides to spare Izuku, saying that there is worth in keeping him alive Stain prepares to kill both Tenya and the Pro Hero since they according to him have no worth. Izuku yells at Stain to stop but to no avail. Suddenly, a column of fire and a column of ice attack Stain, but Stain manages to avoid the attack of fire and ice in the nick of time. Shoto reveals himself, being the one that attacked Stain with fire and ice. While Izuku and Tenya are surprised at Shoto's arrival, Shoto tells Izuku that Izuku didn't text the message specific enough, which caused him to arrive almost late; Tenya is surprised to see Shoto and Izuku is shocked that Shoto not only came but is using his fire power as well

Shoto begins his battle with Stain; Shoto attacks Stain with ice but Stain dodges. Shoto launches a stream of fire at Stain only to be dodged. Shoto's attacks of ice and fire manage to bring Izuku and the injured Pro Hero to him; Shoto states to Stain that he won't let him kill them. Izuku warns Shoto not to let Stain draw his blood. Stain throws his dagger at Shoto's face and manages to land a cut on Shoto's face; Stain appears before Shoto and attacks him with his dagger, but Shoto blocks Stain's attack with a pillar of ice. Shoto looks up in the air and sees Stain's katana, becoming distracted. Stain grabs the distracted Shoto and prepares to lick the blood off his face. However, Shoto activates his fire power and knocks Stain back, preventing the Hero Killer from ingesting Shoto's blood. Shoto attacks Stain with ice again, but the Hero Killer dodges and slashes at Shoto with his katana and dagger, although Shoto is able to defend himself with a small wall of ice.

Tenya begs Shoto to stop fighting as this is his fight since he inherited Ingenium's Hero name, causing Shoto to criticize Tenya for making a vengeful, saying the Ingenium he knows would not make a face like his. Shoto creates and attacks Stain with great pillars of ice, attempting to block Stain's view. Stain cuts through Shoto's ice pillars with ease. Stain throws two small daggers into Shoto's left arm, causing it to bleed. Stain jumps into the air and prepares to stab Shoto with his katana. Izuku realizes that he can move and activates One For All Full Cowl. Izuku, using enhanced jumping speed, appears before Stain and grabs him, attempting to throw him onto the ground. The Hero Killer retaliates by knocking Izuku away with his elbow, causing Izuku to fall onto the ground. Izuku informs Shoto that he could have been released from Stain's Quirk due to either the number of targets thinning the effect, how much blood Stain has ingested or blood types; Stain praises Izuku for figuring out his Quirk has to do with blood types Shoto tells Izuku that avoiding close quarters combat and holding out is their best course of action against Stain with Izuku agreeing with him, telling Shoto that he will draw Stain's attention while he acts as support. Shoto states that they will protect Tenya and the Pro Hero. Tenya starts to feel regret for his actions as he has not been acting like a Hero should be.

Izuku and Shoto team up to battle Stain. Izuku activates One For All Full Cowl and tries to attack the Hero Killer, but Stain slashes at Izuku with his katana, causing Izuku's leg to bleed; Stain licks his katana and activates his Quirk, which paralyzes Izuku; Izuku apologizes to Shoto as Tenya tells them to stop. Shoto replies that if Tenya wants to stop them he must stand up. Now that Izuku is immobilized, Stain sets his sight on Shoto; he cuts through Shoto's wall of ice, removing Shoto's defense and prepares to attack the defenseless Shoto. Shoto encourages Tenya to set his eyes on the man he wants to be. Tenya remembers that he wants to be like his brother, Ingenium and tries to break free of Stain's Quirk; there is some movement in his hand.