WARNING: The following contains spoilers for My Hero Academia Season 5, Episode 3, "Clash! Class A vs. Class B!", now streaming on Crunchyroll, Funimation and Hulu.
Episode 3 of My Hero Academia's fifth season sees Deku confronting his strange One For All focused dream. In it, the first wielder of One For All offers a cryptic warning, saying, "Be careful. We're long past the singularity point." Deku wakes up from the dream with a strange explosion of his power tearing up his room and is left confused by what his predecessors hope to teach him.
Deku turns to All Might for potential wisdom, but unfortunately, it seems the young hero's experience is new even to his mentor. Still, Deku can't dwell on it as he must quickly join his classmates for an upcoming training exercise with Class 1-B. The biggest surprise of the episode is the reintroduction of a character we've barely seen since the Sports Festival: Shinso.
The dream leaves Deku unable to sleep, hoping to jog off his issues and think about what it could mean. Later, when he meets with All Might, the former Number 1 hero explains his understanding of One For All. Up to this point, All Might believed what his master told him when he was starting: visions of the predecessors are just "vestiges" of these individuals. The predecessors left their mark on the Quirk, so a wielder of One For All will occasionally experience traces of their personalities.
All Might breaks down the singularity theory, which details a perceived future where Quirks will become so powerful that they'll be uncontrollable. They also discuss how All Might was somewhat harder to see (along with two other obscured figures). Deku's theory is that it's because he was a recent wielder of the Quirk. As the two continue discussing, bonding over how pretty All Might's master was, they run into Aizawa and Shinso Hitoshi.
Shinso -- a General Studies student who aims to join the hero course -- last had a prominent appearance during the Sports Festival where he nearly defeated Deku with his Brainwashing Quirk. The interaction is cut short as Aizawa instructs Deku to get ready for practical training, warning him that it will be challenging.
Everyone debuts their new winter costumes at the training area before Class 1-B joins the fray, and some light, competitive banter is thrown among the students. Monoma characteristically mouths off the most -- much to the embarrassment of the rest of his class. Still, Monoma is tapping into more profound tensions between the two classes, and considering it's their first joint combat training, everyone's excited to see how they fare.
Aizawa and Vlad King arrive (with Aizawa quickly choking out Monoma to shut him up) and introduce Shinso as a special participant in the exercise. Shinso wants to transfer into the hero course, and this training is a chance for him to prove himself. Shinso follows suit with the other students and shows off an improved costume -- now sporting an interesting mask, and binding cloths like Aizawa wears. Though not explicitly stated, it seems as though Aizawa is taking Shinso under his wing, training him personally. Considering the tactics behind their Quirk usage (and appearance), it looks like an exciting prospect.
As we see in a brief flashback, Shinso is aware that his Quirk would be easy to abuse, but he wants to be a hero and help people, as he says to Class 1-A and 1-B. Even with his powerful Quirk, Shinso knows that he is a long way behind his peers and tells them all that he's not there to make friends. He will go all-out to achieve his dream, which means crushing anyone who gets in his way. The classes respond quite cheerfully to this Plus Ultra declaration, with Deku especially excited for a new challenge.
The drill will consist of groups of four facing off against each other, head-to-head, viewing their opponents as villains they are aiming to capture. To keep things fair, Shinso will take a turn playing on each side -- once on a Class 1-B team, once on a Class 1-A team. It turns out that he'll fight in the first match alongside Class 1-A, specifically with Asui, Kirishima, Koda and Kaminari. His turn with Class 1-B will be in the final one, against Uraraka, Mineta, Ashido and Deku.
The first round begins with the Class 1-A squad placing most of their concern with Shiozaki and her Vines Quirk -- which she easily defeated Kaminari with at the Sports Festival. Shinso says they should take Shiozaki down first, as she is the most powerful enemy; however, they're ambushed as they're discussing a game plan.
Asui and Kirishima are quickly taken down by Shishida, using the immense physical power of his Beast Quirk. Meanwhile, Koda is stalled by Tsuburaba, who uses his Solid Air Quirk to trap him in a cube. Though things aren't going well for Class 1-A, Shinso turns it around as he reveals the power of this new mask, Persona Cords. With it, Shino can perfectly imitate Tsuburaba's voice, commanding Shishida to attack. Since Shishida responds, he's now under Shinso's control.
The episode ends with Shinso in control, debuting a devastating addition to already-powerful Quirk -- and Deku and the rest look on with awe as the hero-hopeful makes a Plus Ultra impression.