Quirk:

Shadow Manipulation/Dark Manipulation

     She is capable of solidifying darkness, able to take it from her own shadow or other people's shadows, even.

     When it's dark her shadow quirk is much weaker, of course. She and others don't have a shadow when the moon isn't full, or when clouds are blocking it. But that's when she can use the darkness around her to her advantage.

     With other people's shadows, she can create solid darkness in the form of tendrils or chains to bind them. From her own she can create the same, but the tendrils can only go so far when they're from a shadow; darkness is more effective for that.

     She can make a person's own shadow attack said person, even allow the shadow to strangle them. When she's using your shadow, the shadow stands up and walks like a normal person, so then you have no shadow on the ground. Imagine her taking you by surprise; you won't notice until someone points out that you don't have a shadow.

     As she practices it, she'll learn that she can use more than one shadow at a time and create large creatures from the dark.

     She can create not only weapons from the darkness, but ways of transportation. She creates creatures of solid dark so she can travel faster, and she can go into her own shadow to be able to teleport somewhere. How that works, no one is exactly sure, she just knows that she's able to do so. She believes that it simply allows her to go at a greater speed so that it seems like she teleports.

     She is also capable of creating a shadow clone. This is done by her forming a solid figure of her shadow and making it look like a person, then it takes on an appearance that makes it look and sound just like her. Since it's basically her shadow in living form, it even has her memories and it acts just like her. However, she can only create clones when she has a shadow, of course, and it'll disappear if light is blocked, causing shadows to disappear. She can create shadow clones by using other people's shadows, too. Meaning they could kidnap someone and create a lookalike to take the person's place to gain information. However, using someone who can shapeshift is best, considering the shadow clone will cease to exist if something were to block a shadow, such as a cloud in front of the moonlight, or the sun being blocked by gray clouds.

     When the sun is blotted out by clouds, or when it's dark, she can't use shadows. Controlling shadows is her most dangerous ability, but she's still dangerous when the darkness is all around, as she can create weapons and creatures made of darkness. The only thing that can vanquish them is the light.

     Because of being able to control darkness, she'd be capable of controlling Tokoyami's Dark Shadow quirk.

     Considering she can't use her darkness quirk when there's light, she becomes weakened by light. During the day she gets her strength from shadows. When she has no shadows and is trapped by light, she becomes weak to the point she passes out.