All For One (Quirk)

All For One is the Quirk used by All For One, before being transferred to his son, Akatani Mikumo, while keeping a duplicate but weaker version.

A even more weaker version of the Quirk was also used by Nine.

Zoey accidently created a duplication of both All for One and One for All through the magic of the Heart of Kandrakar.

## Usage

All For One allows the user to steal Quirks from anyone they touch for personal use, or transfer the stolen Quirks to anyone.

The process of giving and taking away Quirks is done through touch, through a hole in the palm of the user's hand, once it receives contact.

A victim whose Quirk has been stolen becomes Quirkless, and loses any abnormal features if the powers happened to be Mutant-types.

Interestingly, even if the user holds Mutant-type Quirks, the subsequent features do not permanently manifest on the user's body, and they can instead summon the mutant features at will.

Additionally, when a Quirk is stolen, the victim becomes disoriented and immobile for a short time.

Meanwhile, Quirkless people who receive a Quirk through All For One become capable of manifesting all of its attributes.

Rarely, a Quirk granted by this ability can blend together with the recipient's original Quirk, creating an entirely new power, as shown with One For All.

In addition, it is also possible for the Quirks stored within All For One to evolve and grow stronger when mixed with other Quirks, as demonstrated with All For One's lie detection Quirk that he stole when Quirks first began.

All For One can be used to combine several Quirks in order to create devastating techniques, which would normally not be possible with the usage of only one Quirk.

Furthermore, it can also be used to help restrict a Quirk’s drawbacks and weaknesses through the usage of other Quirks, allowing the user to easily handle multiple powers without facing repercussions to their body.

## Weakness

There are some limitations to the Quirk.

Not all recipients of a Quirk from All For One are able to handle the strain of gaining them, subsequently becoming mindless dolls, who are not able to speak or think for themselves.

Being Quirk-empowered prior to receiving a Quirk from All For One is a factor that allows a person's body to withstand the Quirk-bestowal process.

This spectacle was evident when Yoichi Shigaraki, Wolfram, and Lady Nagant were not put into brain-dead states upon being endowed with a Quirk by All For One, due to already being in possession of their own respective Quirks.

Despite this, being Quirk-empowered does not guarantee a person can withstand the strain, as Spinner's mind became more unhinged after having received two extra Quirks from All For One, causing him to behave more irrationally and violently.

However, even if a person is capable of holding their new Quirk, it is possible that their body would not be able to properly handle its power.

The effectiveness of the Quirks that are stolen by All For One depends on his own abilities.

He stated that he did not want to steal Best Jeanist's Fiber Master, as it required too much training and experience to truly master, this implies that he prefers to steal Quirks with straightforward abilities.

All For One is incapable of stealing One For All from its wielder, as that Quirk, by its very nature, can only be passed on if the present wielder wills it.

Thus, wielders of One For All can act as a natural counter of sorts against All For One's ability to steal other Quirks.

However, he was able to overcome this limitation in the past against previous wielders of One For All, due to the sheer number of Quirks he possessed.

It's been discussed by Kyudai that, over time, the large number of accumulated Quirks within All For One was becoming dangerous to the user himself.

While it seemed that All For One could allow the user to safely control any number of Quirks, there is a limit to how much the user can control without it adversely affecting them, like the Nomu.

Kyudai went on to state that if the "memory" (the amount of power of a Quirk) exceeds the "hardware" (the body of the Quirk user) then it will cause serious problems.

This is somewhat similar to One for All, which causes a serious burden on the user's body and can shorten their lifespan if they already possess a Quirk when receiving it due to the burden of possessing multiple Quirks.

As all Quirks are tied to their user's body and have been stated to be a function of the user's physiology much like an organ or limb, as such, injuries or negative health conditions will limit a user's Quirk or their ability to use it.

This is even more pronounced with All For One, as the ability to use stolen Quirks along with how many Quirks can be stolen is directly connected to the health and strength of the user's body, the user's ability to steal Quirks and use them is drastically diminished if they become injured or crippled.

After his fight with All Might, All For One's permanent, life-threatening injuries drastically reduced his power and output with his Quirk, forcing him to come up with a way to either heal himself or strengthen and take a new body to recover and surpass his previous limits.

All For One only has the ability to give and take Quirks from others, it does not allow the user to destroy the Quirks they hold, even if they threaten the user's health.

After stealing New Order from Star and Stripe, the hero placed a rule on her Quirk which stated that it would revolt against other Quirks, allowing New Order to severely weaken Tomura's body and destroy many of his Quirks from within.

The only way for an All For One user to rid themselves of a self-destructive Quirk is to transfer it to someone else.

Another possibility would be for the user to gain a Quirk that could heal or negate another Quirk's damaging affects, although this was impossible with New Order as the rule set upon it prevented it from coexisting with other Quirks.

While not an issue for the original wielder of the Quirk, one particular weakness of All For One for an inheritor of the original Quirk variant is the threat of the previous wielder's will taking over the body and controlling the current user, as is the case for Tomura being taken over by All For One.

As described by the vestigial will of All For One contained within the Quirk, negative emotions such as hatred and anger would allow his consciousness to take over the body of its current wielder, as well as shape the body into a whole new being, that is a fusion of the two minds.

With Nine's lower-tier variation of the Quirk, he was only able to steal up to 8 other Quirks.

In his attempt to steal One For All from Akatani Mikumo, Nine was unable to do so, which he believed was due to his storage limit (which was actually the Quirk's anti-theft properties).

It is unknown if Nine's version allowed him to transfer Quirks to other people, as he was never seen nor mentioned to have done so.

Moreover, due to the power of All For One, it put further strain on his body and caused the cellular degeneration from his Weather Manipulation Quirk to worsen.

This drawback is the reason why Nine attempted to steal the Cell Activation Quirk of Katsuma Shimano so that he can rejuvenate his lost cells and continue using his various Quirks without limit.

With All For One's duplicate of his own Quirk, it is revealed during the second war that the copied version doesn't give him as much command over his stolen Quirks as the original.

This has caused some of the vestiges of people he's stolen Quirks from to rebel against him and hinder him in battle.

Since All For One's Quirk Factor resides in the user's hands, they would be unable to use it should they lose said limbs, unless they possess a Quirk that can regenerate and regrow them.

## Users

* Akatani Mikumo (Orignal, Currently)
* Zoey Davidson (Duplicated, Currently)
* All For One (Duplicate, Currently)
* Nine (Duplicate, Formerly)