Possibly incomplete OC as this was an idea I've had rattling around in my head for about a year now. Took a lot of researching as I didn't pay much attention to physics in school and almost made her quirk the ability to absorb momentum only. But after some quick research and help from friends I was able to figure out a more believable version of this quirk.

Critique is appreciated and suggestions on possible edits are also appreciated. Also if this resembles another persons character then know I didn't steal the idea or copy it, it's purely coincidence and I apologize if it is similar to someone elses character.

Name: Chikara Tomerarenai (Force, Unstoppable)

Hero Name: Overwhelm "The Physics Hero"

Sex: Female

Sexuality: Bi

Age: 19

Appearance: Chikara is a tall young woman standing at around 6'0" with a noticeably toned build. Her hair is short, resembling a tomboyish bob haircut and the color is white due to Marie Antoinette syndrome. She's covered in scars a lot like Mirio but her's are focused around the joints of her body and many resemble surgical scars. Her skin is tan and her eyes are a vibrant blue. Lastly her casual attire is a large hoodie borrowed from her classmate and fellow top 3 Mienai as well as some jogging pants with running shoes.

Quirk: Velocity Transfer - This quirk allows Chikara to absorb the velocity and momentum from any object or person in motion. Said energy is stored within her body until she decides to apply the energy to herself. As she uses her quirk whatever object or person she's taking the energy from slows down till it reaches a full stop, any energy propelling it having been absorbed by her quirk.

This allows Chikara to then apply the exact same amount of velocity and momentum to her body, this means if she absorbs the velocity and momentum of a boulder thats been thrown at her she can make her fist move just as fast as the boulder and hit just as hard as the boulder.

Quirk Downsides: Chikara's quirk comes with some very obvious downsides. She can only store so much energy and when her limit is reached the energy will begin to seep out of her body, applying it's affects to random objects and people around her which can cause issues for friend and foe alike. Her quirk also requires immense concentration and timing as the moment she applies the energy to her body her velocity and momentum go from 0-100 immediately which has lead to dislocated joints, torn tendons and muscles, and other more severe injuries. Lastly it still takes time to absorb energy from things which leaves her vulnerable if she's out of energy and unable to find a large enough source to allow her to fight.

Hero Outfit: Chikara's hero outfit consists of the usual form fitting jumpsuit, sleek carbon fiber braces connected to every major joint of her body to mitigate the sudden shift in velocity and momentum, lightweight carbon fiber and titanium protective plating along most of the body, specialized combat gloves and boots to increase damage on impact similar to Deku's Shoot Style Boots, a simple visor that connects to a monitoring system for her bodily health/damage, and a belt with basic support items in case of emergency.

Personality: Chikara is a very blunt and honest woman but this is only because she treasures trust above all else. She's usually very energetic unlike her two friends and fellow top 3 who're either always asleep or always annoyed. Some think her energetic and eager nature come from her quirk but they say that mostly to tease her about how much of an over achiever she is and how everything seems to excite her. She's highly determined and spends most if not all of her free time training, always saying that her body is still too fragile and that she can push it further....despite the fact she scares most people in the school gym with how strong she is. All in all she's a trust worthy and honest friend who pushes herself to far only because she still views herself as weak.

Backstory: When Chikara was born her parents had to put her up for adoption due to financial issues and because the parents knew that they couldn't give their child a good life. So for pretty much all of her life she lived in the orphanage, thankfully she was able to get a good education and grew to be quite the smart young girl. But year after year she found herself turning down potential parents as she didn't want to be a burden, believing thats why her parents put her here in the first place. Over time she grew content with living at the orphanage and working there for a small but modest pay.

Up till now she had yet to discover her quirk and honestly she wasn't that worried about unlocking it as she was perfectly happy working at the orphanage and helping people find the right family to join. However during an intense battle between villains and heroes the orphanage was taken by a number of villains with gun quirks that threatened to harm the children, using them as hostages to fight the heroes.

When one of the villains got tired of waiting for the heroes to listen to their request they fired a bullet off at one of the kids. But the bullets just stopped mid way and dropped to the floor, and in a split second the villain was knocked out with Chikara sobbing and afraid...her arm dislocated in multiple places with her knuckles bloodied.

Since then the orphanage was shut down due to damages and Chikara was allowed to stay with one of the employees there. After some time recovering in the hospital and getting some tests done concerning her quirk she had finally learned what she could do.

With this new knowledge she decided to apply for UA, not because she wanted to be a hero but because she wanted to fund a new orphanage and hopefully save more children from becoming orphans like her due to villains killing their parents.

Now she's one of the big 3 of UA and even now her goals haven't changed, she's just gotten more determined over the years and looks to have a bright future ahead of her.

Ultimate Move: Unstoppable Force - This ultimate move involves Chikara applying large amounts of energy to her whole body at once instead of just a single part of her. This move makes her whole body burst forwards at speeds almost invisible to the naked eye with the added force of everything she's stored up till this point. This is a double edged sword as the quirk only applies the velocity and momentum to her body and doesn't enhance her reaction speed or perceptive ability meaning that changing directions in this state is pretty much impossible so if she misses her target then she'll crash into whatever is around her at full force likely injuring her greatly and putting her out of the fight.