User blog comment:RyanTheScourgeOfTheStorm25/Quirk Ideas?/@comment-25044056-20180501224218

Hypergravity (高重力, kō jūryoku): belongs to Toshi Midoriya of the gravity twins, allows her to increase the effects of gravity on objects she touches, making them very heavy and nigh-impossible to move. By using this ability on other objects or people, Toshi can crush them, slow them down, or immobilize them. By using this ability on herself Toshi it makes her nigh-impossible to move or lift by external force but she has trained her body so that she can still move herself however. Training her body under high gravity conditions means that when she's not in those conditions she's incredibly fast and strong.

Subgravity (低重力, tei jūryoku): belongs to Nori Midoriya of the gravity twins, allows him to reduce the effects of gravity on objects he touches, making them very light and easy to move. By using this ability on himself he can increase his own mobility and slow his descent as he falls. By using it on other objects Nori can simulate super strength, but bear in mind it is still just a simulation, he needs to touch the object in question with the tips of his fingers first. Using Subgravity on an opponent directly is dangerous because while it could allow Nori to send his enemy flying with an attack, it could also give his enemy increased mobility until the effect is released.