Deku's inheritance of One For All and his combat training throughout My Hero Academia provide him with a considerable range of abilities. His numerous villain encounters and battles against teammates put his growing skills on full display. However, not all of Deku's heroic abilities frequently get put into practice outside severe circumstances.
Deku's most unpredictable hero skills rarely appear on the battlefield due to their physical strain or the difficulty of controlling them. The drawbacks of Deku's Quirk and the consequences of wielding its full power limit how often Deku can reliably use it in the anime without the risk of permanent injury.
This article contains spoilers from the My Hero Academia manga.
10 Deku Rarely Uses One For All At Maximum Power
Deku demonstrates the ability to wield One For All at 100% power, yet he rarely does so due to the injuries the action causes. Deku only taps into One For All's full potential during life-or-death moments, such as when he uses a maxed-out One For All to defeat Muscular. Using One For All without restraint risks Deku's life and serves as a last resort.
Deku fights the majority of his battles with One For All within a limited range of 45% or less strength. He lacks the muscular strength to endure One For All's demands all at once.
9 Deku Uses The Quirks Of One For All's Predecessors Sparingly
Deku's struggle to control the Quirks of One For All's predecessors causes him to limit his use of them in battle. Using his inherited Quirks without caution leads Deku to unintentionally injure those around him, as seen when he hurts Uraraka with Blackwhip. Deku only utilizes his extra Quirks after taking the time to practice them without the risk of endangering others.
Deku relies on One For All as his main combat Quirk and relegates his less understood Quirks to supportive roles against tricky opponents. He views One For All's hidden Quirks as potential liabilities to work around.
8 He Limits The Use Of His Hero Notebook
Deku uses his hero notebook to assess his rivals' abilities yet rarely visually records information on villains. Though Deku's strategies in the heat of battle often succeed, writing down the known strengths and weaknesses of recurring villains provides an advantage that Deku misses. He relies on his memories of villain Quirks to formulate plans without collecting written data from encounters.
Deku grows as a hero without relying on his notebook yet has access to a method of storing information that could help other heroes survive villain encounters. Having updated written information becomes increasingly crucial as villain Quirks like Decay evolve.
7 He Rarely Makes Full Use Of His Physical Strength
Deku possesses extraordinary strength that allows him to endure One For All and maneuver around environments with ease. While Deku incorporates his physical strength into his punches and Shoot Style maneuvers, he rarely utilizes his strength to wield heavy objects as weapons.
Deku's ability to lift vehicles with One For All's assistance provides an attack method that Deku barely touches upon. One For All's strength enhancements give Deku opportunities to use rubble or nearby structures as support weapons if needed.
6 Deku Transfers One For All Once
Deku holds the ability to transfer One For All like All Might before him, yet he only enacts this once. Deku passes One For All to Bakugo to defeat Nine, though Deku retains his Quirk due to the intervention of previous successors. His dream of upholding All Might's legacy keeps Deku from giving up his Quirk without good reason.
Deku considers abandoning One For All's responsibilities as a failure and transfers the Quirk out of pure necessity. His determination to use One For All to protect others keeps his dream alive despite the usually permanent consequences of a transfer.
5 Deku Gets Few Opportunities To Use Froppy Style
Deku excels at studying his allies' techniques and learns to shoot his Blackwhip Quirk's tendrils from his mouth in imitation of Froppy's fighting style. Deku's new technique requires consistent control over Blackwhip which he only attains in the manga's later chapters, which provides him limited opportunities to use it.
His unique method of wielding Blackwhip appears out of desperation and the inability to rely on his usual attacks. Deku uses Blackwhip's additional ability to reach opponents over longer distances and continue fighting in a weakened state. His use of Froppy-style combat shows his determination to reach his objectives without fail.
4 He Has Yet To Use The Quirk Of One For All's Second User
Deku receives no chances to use the Quirk of One for All's second user after its previous wielder advises Deku to use it as a last resort. My Hero Academia has yet to reveal the mysterious Quirk's abilities, which leaves Deku to hold back on using it in combat.
The Quirk's heightened destructive power after its assimilation with One For All makes it riskier than other inherited Quirks. Deku's unrevealed Quirk has a future role in the ongoing battle against All For One's forces. Deku continues to wait for the right moment to unleash the Quirk's full capabilities.
3 He Visits One For All's Vestige World Infrequently
Deku seldom interacts with One For All's previous successors within the vestige world due to the difficulties of manifesting himself within it. His increasing mastery of One For All enables him to trigger the vestiges subconsciously and receive advice from past wielders.
The rare chances he gets to interact with the realm's inhabitants while alive grants Deku valuable information on controlling his growing abilities. Deku works diligently to prove his ability to endure One For All's burdens to every previous successor who doubts him. He unlocks a greater potential within himself thanks to his conversations with past legendary heroes.
2 Deku Only Maintains The Strongest Full Cowl Under Strict Conditions
Deku frequently uses his Full Cowl ability to reduce strain on his arms yet takes care not to use its maximum power for long. A 100% Full Cowl risks inflicting irreparable damage and only proves possible for Deku to endure with the help of Eri's rewind Quirk. Deku restricts the power output of his Full Cowl technique with the same caution as his One For All punches.
Full Cowl still requires Deku to manage his physical limits despite its wider distribution of One For All's energy. Deku's current limitations prevent a max Full Cowl from becoming a common strategy.
1 Deku's Delaware Smash Has A High Cost
Deku receives a limited number of uses for his air-pressure-fueled Delaware Smash technique due to the damage it inflicts on the fingers. Although Deku never hesitates to break his bones in combat, his chances to use it in a given battle remain dependent on his number of usable fingers.
His development of Shoot-Style largely renders sacrificing fingers with Delaware Smash unnecessary. Deku's initially poor control over One For All's power output forces him to rely on risky techniques like Delaware Smash as a new U.A. student. He builds off Delaware Smash to develop more effective uses of his Quirk.