One of my fave ninja boys
Quirksona/BNHA OC. Here's the block of text about her quirk if you're interested:
Kaiya has the ability to shift her weight dramatically at will by manipulating the atoms of her body basically. Her default weight is 125 pounds, but she can get as low as .001 pounds. Theoretically, there is no limit to how heavy she can get. She can remain heavy for about 10 minutes and remain light for about 10 minutes, meaning she can use her ability about 20-25 minutes in total if she alternates between them. If she spends too long with her weight lightened she gets lightheaded, and after 10 minutes she will get dizzy and even pass out. If she stays heavy for too long she will get a splitting headache (a little different than being lightheaded) and staying too heavy for too long will also cause a blackout. In addition, when she is heavy she burns a lot more calories, therefore she has to consume a lot of food after she uses her quirk.
As well as manipulating her entire body weight, she can manipulate certain parts of her body, I.e. make one of her firsts or legs heavy so it will deliver a stronger punch/kick. This is risky though; although it uses less energy, the force of swinging around a heavy appendage could send her flying around 30 feet.
In the heat of battle she has trouble discerning where she's at in regards to her time limit, so her left bracelet beeps when she's been light for too long and her body is starting to give out. The right bracelet beeps when she has been heavy for too long. And since there is no upper cap on how heavy she can get, her belt will beep if she gets what becomes dangerously heavy, where the G-forces are starting to put strain on her body as well as her quirk. She can only get to about 10,000 pounds (10 tons) before G-forces start affecting her body.
She can only control her own weight, she can't manipulate the weight of those she touches or whatever.