Poltergeist allows Reiko to telekinetically manipulate objects and people close to her. 
Reiko displays great control over her Quirk, being able to move large swarms of objects in order to barrage a target.
While strong, Poltergeist has the caveat of Reiko's maximum limit being approximately the weight of a single person. And since body weight various between different people, it's dubious for Reiko's limit being the average poundage of a person: 137 pounds.
It is currently unknown if the Quirk has any limitations in regards to the number of objects that Reiko can control.
- Poltergeists are a type of spirit or ghost that is responsible for causing physical disturbances through supernatural powers like telekinesis.