All Might

"All will be well now. Why? Because I came!"

- All Might's slogan

Toshinori Yagi (八木俊典 Yagi Toshinori), more commonly known as All Might (オールマイト Ōrumaito), is the former No. 1 Hero and the eighth user of the One For All Quirk and one of the main deuteragonists of My Hero Academia. He also teaches Foundational Hero Studies at U.A. After fighting against All For One where he used up the leftover embers of One For All completely to defeat All For One, All Might retired from crime fighting, and thus, ending his era. And replaced by his rival, Endeavour as his successor as the No. 1 Hero.

Appearance
In his hero form, Toshinori is extremely tall and overly-muscular man, whose design resembles a generic American comic book superhero. His hair spikes on top of his head and his whole body has more shadows than any other character in the series regardless of the time of day, furthering his stylized appearance. His Hero Costume consists of a red, white, and blue bodysuit with golden gloves and boots. It has been shown with and without a cape. Overall, its design is considered very classic.

In his true form, he is an overly-skinny man with angular features, long limbs, and neck. He has spiky, disheveled hair with two bangs framing the sides of his face and loses his eyebrows from his hero form. He possesses a large scar that covers most of the left side of his chest, and it is not uncommon for him to spout blood from his mouth when excited or surprised. He typically wears baggy clothing to accommodate his Quirk's size change.

Note that in both forms, his eyes are sunken in, but the difference is that you can see his eyes in his true form.

Personality
Toshinori's hero persona derives much from American superhero stereotypes, in which they are colorful and have a lot of dramatic flairs. Always sporting a giant smile, he usually shows off a bright, can-do attitude that borders on being obnoxious. He also tends to be extremely friendly and amicable, due to his popularity and years in the spotlight. However, when he reverts to being sick and scrawny (as a result of a previous battle), he tends to be less energetic due to his constant blood-spitting. Additionally, he tries not to draw much attention to himself while in his true form, always afraid that others might learn of his current state of health.

Two personality traits always persist, though, whether he's in hero-mode or normal-mode: his optimism and his oafishness. He has always had faith and hopes that someone would come along, worthy enough to bear the "One for All" Quirk. He is sometimes depicted being outsmarted by his students, and even his fellow teacher, Shouta Aizawa has called him an idiot a few times.

While he is seen smiling, laughing, and cheerful most of the time, he was shown to be furious when he learned Villains were trying to get to him through his students. Even Izuku was surprised to see such a reaction. He was willing to use his Quirk beyond his time limit in order to save his students.

He possesses a fatherly attitude towards his students (Izuku in particular), which he often hides and keeps to himself. He is quick to give encouraging advice to them when the situation calls for it. He is proud of their accomplishments.

Former Quirk and Abilities
One For All (ワン・フォー・オール Wan Fō Ōru?): Toshinori's Quirk is called One For All and is unique in that it is transferable, with each holder of the quirk responsible for protecting society and strengthening the quirk's power before passing it along, with All Might being the eighth holder. One For All stockpiles energy, and then converts it into overwhelming kinetic power on command, granting All Might superhuman strength, the ability to create powerful shockwaves using his punches, superhuman speed, greatly enhanced agility, enhanced reflexes, high durability and the ability to jump really high. Normally a recipient of the quirk must first undergo intense physical training to avoid being killed by the transfer process and then continue to work on developing their body in order to use more of One For All, but Toshinori was notably able to use all of the quirk's power right away. Overall Abilities: Toshinori is an extremely powerful Hero as he is recognized as the "Symbol of Peace", indicating his extraordinary and immense power. He is able to defeat a Noumu created specifically to combat him. Toshinori, despite his weighted handicap and depleted strength, is easily able to overwhelm Izuku and Katsuki, who are among the strongest in Class 1-A. Toshinori defeated All For One, an extremely powerful villain who once ruled Japan, making Toshinori the only successor of One For All to achieve this feat. The amount of time he can use his One For All abilities have drastically fallen from when he was in his prime because of an injury he sustained from his fight with All For One. After passing on One For All to Izuku, his time limit has started to decrease and after his battle with All For One, Toshinori loses the ability to use One For All. Immense Strength: Toshinori's Detroit Smash is able not only to defeat a villain but also to change the weather shortly afterward. He is able to cause collateral damage to a city block with one punch while being handicapped with great weights, despite becoming severely weakened since his first meeting with Izuku. During his later fight with All For One, he was still able to clash directly with one of the latter's attacks and cancel out its highly destructive power with brute strength alone. Immense Speed: In conjunction with his immense level of physical strength, Toshinori possesses an equally impressive amount of speed. During the USJ Arc, he is able to travel a remarkable distance from the gate and simultaneously incapacitate five villains in the blink of an eye. He disappears from Tomura's sight, strikes him, and intercepts Noumu while the latter is about to attack Katsuki, despite Noumu's showing of being on All Might's level himself. Immense Durability: Toshinori has extreme durability. During the villain's invasion of the USJ, he manages to block a direct attack from Noumu and later takes many attacks from him during their physical bout. During his fight with Izuku and Katsuki at the End of Term Test Arc, he is able to take several of Katsuki's unrestrained explosions without as much as being slowed down. All Might was able to survive All For One's blast wave attack, a move that can cause city-wide catastrophic damage, and emerged unharmed with only some minor scratches.
 * Texas Smash (テキサススマッシュ Tekisasu Sumasshu?): Toshinori throws a right punch with enough force that the wind pressure sends anything made of liquid flying away. This move is first used to save Izuku from an unknown enemy.[4]
 * Detroit Smash (デトロイトスマッシュ Detoroito Sumasshu?): Toshinori preforms that same attack as Texas Smash except this move is with a downward punch instead of a straight punch. The punch is powerful enough to create a shock wave large and powerful enough to clear the weather. This move is first used to save Izuku and Katsuki from an unknown enemy.[5]
 * Missouri Smash (ミズーリースマッシュ Mizūrī Sumasshu?): Toshinori runs towards an enemy while keeping his hand flat and hits the enemy on the head while running past them. This move is first used against Trapezius Head Gear.[6]
 * Carolina Smash (カロライナスマッシュ Karoraina Sumasshu?): Toshinori runs towards an enemy while keeping his hands in a cross position, then in a downwards cross chop to the enemies head. This move is first when against Noumu.[7]
 * New Hampshire Smash (ニューハンプシャースマッシュ Nyūhanpushā Sumasshu?): Toshinori blasts himself towards his enemy and smashes his body into the enemy, crushing and injuring the enemy with his great weight. This move is first used to propel himself at Izuku.[8]
 * Oklahoma Smash (オクラホマスマッシュ Okurahoma Sumasshu?): Toshinori whirls around while enemies have latched onto him, spinning with enough force that when they are released they are easily thrown through concrete. This move is first used against Noumu.[9]
 * United States of Smash: Using all his power, Toshinori delivers a massive punch, powerful enough to send shockwaves reverberating the surrounding area; it was powerful enough to incapacitate enemies of extraordinary caliber such as All For One. Toshinori first used this move to defeat All For One.

Trivia

 * All Might's real name contains the kanji for "eight" (八), "tree" (木),"genius" (俊) and "law" (典).
 * All Might likes movies.
 * All Might's phone is red.
 * All Might's signature moves are named after states and cities in the United States.
 * In the First Popularity Poll, All Might is ranked 5th, which currently makes All Might the most popular Pro Hero and U.A. teacher in My Hero Academia.
 * All Might has a habit of calling those who are younger than him "my boy", in his mind or while talking to them directly. He also has the habit of saying many English words.