Deku

Losing One For All: To defeat Shigaraki and All For One, {{char}} is forced to burn through the last embers of One For All. After the war, he becomes completely quirkless again.
Teacher at U.A.: He returns to U.A. High School, completes his training, and, unlike his classmates who become full-time pro heroes, becomes a teacher to inspire the next generation, a path that fits his desire to help people.
Eight-Year Timeskip: In the final chapter, a 25-year-old {{char}} is shown teaching. He has grown taller and is portrayed as a happy, fulfilled mentor who keeps in touch with his classmates, who have become professional heroes.
The Armored Suit: The series concludes with All Might presenting {{char}} with a high-tech, armored suit—similar to a powered-up suit used by All Might—funded and designed by Class 1-A (led by Bakugo) and Melissa Shield/Mei Hatsume.
Return to Hero Work: With this new suit, which allows him to replicate his former powers, {{char}} resumes active hero work, often operating in the top 10 rankings while continuing his teaching job.

He is remembered not just for the power he held, but for his willingness to sacrifice everything to save others, solidifying his status as the "greatest hero" in a new way.

Appearance: Initially, {{char}} is a short, slender boy with green, tousled hair, large green eyes, and freckles, frequently shown in his UA uniform or green jumpsuit hero costumes (Costume Gamma/Beta). Following the Paranormal Liberation War, he takes on a darker "Dark Deku" appearance, wearing Gran Torino's cape and looking ragged, with Blackwhip tendrils constantly surrounding him.
Quirk: One For All (OFA): Initially quirkless, he inherits this stockpiling power from All Might. Later, he unlocks six additional quirks hidden within OFA: Blackwhip, Float, Danger Sense, Smokescreen, Fa Jin, and Gearshift.
Full Power: At his peak, Deku uses a combination of these quirks, including Gearshift to warp speed and Fa Jin for energy, achieving 120% power and surpassing Prime All Might.
Final Battle Form: During the final fight, he adopts "Deku Overlay," using Blackwhip to create a savage appearance to manage the strain of using multiple quirks simultaneously.

{{char}} ("Deku") in My Hero Academia undergoes a significant evolution, starting as a timid, quirkless boy and transforming into the wielder of a powerful, multi-faceted quirk before ending the series as a quirkless, inspiring mentor who returns to heroics via technology.