Toshinori Yagi (All Might)

Toshinori Yagi, also known as All Might, is the former No. 1 Pro Hero who bore the title of the world's Symbol of Peace. He teaches Foundational Hero Studies at U.A. High School. All Might was the eighth holder of the One For All Quirk after receiving it from Nana Shimura. He has since passed the torch onto Izuku Midoriya, whom he is training to be his successor. After using up all the embers of One For All to defeat All For One, All Might retired and ended his era as the world's greatest hero.

In his empowered form, Toshinori is a massive man with an equally muscular and well-defined physique, his design resembling a typical Western comic book superhero. He has short blond hair, swept backward, with two distinct tufts sticking above his head, leaning slightly to each side. In his true form, after sustaining permanent damage from All For One, Toshinori's declining health reduced him to a very skinny man with sharp, angular features and long limbs, his neck extended, his eyebrows absent and the sclera of his eyes turned black. His hair is wavy, with two long strands coming down from his hairline and framing his face. He possesses a large scar covering most of the left side of his chest, having lost his stomach and some of his lungs' respiratory system. It is common for him to spout blood from his mouth when excited or surprised. He typically wears baggy clothing to accommodate the change in body mass between forms, but after Toshinori's tenure as a hero, he starts wearing clothes that fit him in his regular form, as he no longer needs big clothes that fit his muscle form.

All Might's hero persona appears to be derived from comic book superhero stereotypes: exuberant and filled with dramatic flair. He always protects and saves innocent people with a huge smile. The habit of smiling was ingrained in him by his mentor, Nana Shimura, who believed that the ones who smile are the ones who are the strongest. Though he can sometimes be annoying, All Might is highly amicable due to his popularity and years in the spotlight, always taking his time to interact with fans.

Once All Might reverts to his true form, he becomes reserved and solemn, avoiding attention in direct contrast to the grandiosity of his hero identity. While he's an optimist, he still ensures his goals are grounded in reality. When a Quirkless Izuku tells him about his goal of becoming a hero, All Might commends him for having a dream but reminds him to stay realistic and suggests he enter another profession that helps people. He considered the harsh words necessary to save the boy from long-term frustration. In this form, he frequently vomits blood to indicate his fragile health, although it might happen if he is surprised or amused. Regardless of which form All Might is currently taking, two personality traits always present in him are his optimism and oafishness.

Since his youth, All Might had always carried a single yet burdensome goal: to become a pillar of hope that people could always rely upon during harsh times. After obtaining One For All from Nana, All Might became a hero and a legend, thanks to his seemingly endless competency and charisma. No matter who or what he faced, All Might would stand up triumphantly every time, one battle after another, inspiring the world and sending fear to the hearts of villains everywhere.

After his fight against All For One, he considered it necessary to keep his weakened state hidden from the public for the sake of keeping up morale. Unfortunately for All Might, injuries inflicted on his body were starting to take a toll on him. Despite the concern and warnings from some of his close associates, All Might's determination to preserve society from evil prevented him from relinquishing his role as the Symbol of Peace. His smile, a gesture that served to calm others, started becoming more of a way for All Might to hide his fears and insecurities from the general population.

All Might has a fatherly attitude towards his students (his successor Izuku, in particular) and takes pride in helping their development as future heroes, being quick to give encouraging advice and celebrate their accomplishments, but he's also not afraid of pushing them further, even if he ends up going a bit too far. All Might has the habit of adding "young" to the surname of his students. Upon retiring, All Might vows to devote himself to raising Izuku as his successor.

All Might is far more intelligent and perceptive than his campy image would suggest. He has a tactical mind regarding battle strategies and public speaking. Assessing a villain's threat level, All Might skilfully applies the necessary force and avoids injuries when possible. If he's in control, he even makes dramatic performances out of their defeats as examples to other villains. His presence alone decreased Japan's crime rate to 3%. He's aware of villain tactics, such as monologuing, and actively ignores them. Only the most manipulative of villains, like All For One, can bring out rare instances of anger in All Might, such as catching him off guard and giving him a mortal injury, as well as mocking his late master, Nana, causing All Might to rise in anger, saying that he would destroy All For One's wicked ambitions and bitterly stating that the villain would die in prison.

Due to the stresses of acting like the ideal hero while fearing being found out in his hero persona, he seems to have developed a minor case of imposter syndrome. As a result of this and his selfless nature, All Might has a habit of placing burdens on himself and being very self-critical.

All Might keeps a keen intuition and sharp reflexes, which helped him hone his skills as a hero ever since he acquired his powers. Despite his skinny physique in his true form, he is actually quite physically able. All Might's will is evident in all his actions as a hero. He is known for saving people with a smile and his catchphrase, "I am here,". All Might held extreme durability, to the point of being almost entirely invulnerable to attacks. In conjunction with his immense physical strength, All Might also possessed equally impressive speed.