TV-Series
Description
Flash l'Abbagliante, also known as Flashy Flash, is a professional hero ranked 13th in the S-Class of the Hero Association. He is a young man with an androgynous appearance, characterized by sharp blue eyes and long blonde hair with a fringe brushed to the right side of his face. His hero costume consists of a dark blue bodysuit with metallic arm bracers, torso armor, and a white cape attached at the shoulders. He wears accessories featuring eight-pointed stars on both sides of his head and on his cape, and a chain around his waist helps secure his sword. He bears a few scars on his chest, evidence of past battles.

His background is rooted in a secretive and brutal Ninja Village, where he emerged as the top graduate of the 44th class. After leaving the village, he was hunted by numerous assassins and criminal leaders, all of whom he eliminated. These targets included figures such as Aburabozu, the king of organ traders; Harold, a drug lord; the heart collector Burigura; and the phantom thief Chimagusa. His actions eventually led to an incident that resulted in the death of nearly all of his graduating class, an event known as "The End." A surviving classmate from the village is Speed-o'-Sound Sonic, with whom he formed a bond during their training; Sonic was the one who taught him swordsmanship.

In terms of personality, Flash l'Abbagliante is generally calm, serious, and discreet, rarely engaging in unnecessary conversation. He carries himself with an air of refinement and dignity. However, this exterior masks a deep-seated arrogance and vanity. He holds a very low opinion of heroes ranked below him, often treating A-Class heroes as insignificant and telling lower-ranked heroes to step aside so he can handle a situation. He has great confidence in his own abilities and believes that rigorous training is the only true path to acquiring strength.

This arrogance extends to his relationships with other S-Class heroes. He is notably unafraid to confront Tatsumaki, scolding her back when she insults him and even claiming she is not as powerful as he is. He harbors murderous intent towards Sweet Mask, disliking his authoritative and egotistical attitude, and often instigates verbal conflicts with Metal Bat. Despite this, he shows respect towards those he considers genuinely strong, such as King, and has praised Shadow Ring's ninjutsu techniques.

His defining trait is a refusal to admit that anyone could be faster or more powerful than himself. When he first encountered Saitama, he mistook the B-Class hero for a monster and attacked him. Even after recognizing Saitama as a fellow hero, his pride would not allow him to accept that Saitama had effortlessly dodged his attack, leading him to attack again. While he found Saitama irritating during their time exploring the Monster Association headquarters together, he became impressed by Saitama's abilities, acknowledging that he was "good enough." After the battle with Garou, Flash witnessed Saitama's overwhelming power and, while acknowledging his strength, decided that Saitama needed a teacher to properly polish his abilities.

His role in the main story includes participating in the S-Class meeting during the Sky Invaders arc and assisting in the fight against the giant monster Hundred-Eyes Octopus in City I. He later joins the surface team and then the underground assault team during the Monster Association raid. In the underworld, he clashes with his former seniors from the Ninja Village, Gale Wind and Hellfire Flame, defeating them even after they transform into monsters. Following the defeat of Garou, Flash spends time searching for remnants of the Monster Association.

Flash l'Abbagliante is a complete and formidable combatant. His primary asset is his tremendous speed, which he uses to deliver a barrage of attacks in an instant. One of his known techniques is the Flashy Fist, where he traverses the distance between himself and an opponent in milliseconds to unleash a flurry of punches. He is highly skilled with a sword but is equally proficient in hand-to-hand combat. His intelligence and tactical thinking make him a versatile fighter, and his physical abilities are such that even before upgrading, he was considered one of the few S-Class heroes capable of defeating a Dragon-level threat. After the battle with the Monster Association, reflecting on Saitama's raw talent, he believed that with the right mentor, Saitama could easily become an S-Class hero.