My Hero Academia's Izuku Midoriya was born powerless, which made him the perfect candidate to receive the incredible Quirk known as One For All. Including Izuku, there have been nine users of the transferable One For All, and some of the Quirk's previous wielders had their own natural Quirk factors while others did not. Though Izuku has made impressive use of his Smash attacks, these additional abilities are something he can incorporate into his fighting style.
Izuku and All Might never had natural Quirks, but One For All's other users did contribute their Quirk factors to its legacy. Izuku has the unique opportunity to utilize his predecessor's Quirks, inheriting them through One For All. So, what are these bonus Quirks that Izuku can wield via One For All, and which ones are the most useful?
5. Smokescreen -- En's Quirk
One of the support-style Quirks built into One For All is Smokescreen, which is fairly similar to the Smoke Quirk. However, Smokescreen has no adverse effect on anyone's eyes. Instead of dealing damage or incapacitating its enemies, Smokescreen allows its user to emit thick, dark smoke from their body and obscure the battlefield with it -- reducing everyone's visibility.
This Quirk can be highly effective for creating an escape route in a problematic situation or hiding the user's approach to an enemy. However, the user can't see through the smoke either, and crafty villains might use Smokescreen's effect against its wielder. Also, there is no (current) potential to create an Ultimate Move for this Quirk.
4. Danger Sense -- Hikage Shinomori's Quirk
Danger Sense is also a non-lethal Quirk, acting as a sensor rather than a weapon. Originally belonging to Hikage Shinomori, Danger Sense allows the user to "feel" when an enemy is about to attack them. It's not quite the same as the Search Quirk used by Ragdoll of the Wild, Wild Pussycats, but it does keep the user on their toes and helps reduce the odds of falling into an ambush.
Naturally, this Quirk is most useful in a cluttered battlefield or urban terrain, where villains or monsters such as the Nomu might be around the corner or behind a closed door. With this ability, Izuku can ruin any villain's opportunity to land a surprise first strike, evening the odds a little. The Quirk can be compared to Spider-Man's Spidey-Sense, though Danger Sense can be painful to use when charged up by One For All.
3. Float -- Nana Shimura's Quirk
The 7th user of One For All was the woman known as Nana Shimura, and she was the one who passed it on to Toshinori Yagi/All Might. Nana Shimura was a melee-oriented hero, like her contemporary Gran Torino, and used her Quirk Float, which granted her the simple but effectual ability to fly around and hover in the air at will. The Quirk offers mobility, giving its user the ability to escape dire situations, assuming the enemy can't fly as well.
Float can also be useful for evacuating someone from danger, and its users can survey the terrain with ease to spot the enemy or find others to rescue. No doubt Izuku will make great use of this Quirk and move in all three dimensions.
2. Blackwhip -- Daigoro Banjo's Quirk
Daigoro Banjo -- the fifth user of One For All -- had a unique Quirk to contribute to One For All. He used the Blackwhip ability, which allowed him to manifest several thick black tendrils from his body to use for offensive moves and maneuverability. For example, Blackwhip can grab onto objects and let the user swing around, like Spider-Man. The user can also hold onto nearly anything to prevent a fall, seize an item or save a person falling, like an extra-long arm.
On the offensive, Blackwhip can grab objects and strike the enemy with them (or throw them), and the Quirk can hit the enemy directly or grab them as they are attempting to flee. So far, Izuku has made great use of Blackwhip in the manga's most recent chapters, showing how effective this Quirk can be.
1. Power Charging -- One For All's Main Ability
Power storage is the primary usage of One For All and is an ability that the villain All For One forced upon his younger brother several generations ago. At first, All For One meant for this Quirk to strengthen his sickly younger brother and restore his vitality, but over time, this ability became the ultimate melee weapon.
Any user of One For All can keep charging up power and release it to form incredible Smash attacks -- not to mention Full Cowling and Shoot Style, Izuku's own inventions. With this awe-inspiring strength, All Might finally took down All For One, and Izuku may one day do the same to Tomura Shigaraki.