Chell

Chell is the main heroine in both portal 1 and 2. She was one of the scientists daughters in aperture science and was made a test subject. Chell has been put through various testing and in the end, has brought down the evil computer GLaDOS.

In portal 2 she is awoken from a slumber by an Intelligence sphere named Wheatley. On the way to escape the facility, Wheatley accidentally reawakens GLaDOS. From then on Chell is forced into more testing until her and Wheatley defeat GLaDOS. When they did so, Wheatley made GLaDOS into a potato and went mad with power. In his rage he sent the duo into the underground facility of old aperture.

Throughout more testing, Chell and POTaTOS find an elevator and confront Wheatley. After a battle which Chell sends Wheatley to the moon, GLaDOS goes back in command and chooses to let Chell go and to not come back.