Three. (UPDATED)

After losing her value, Three seemingly lost some of her powers.

– Electricity generation: Three can fire beams from her hands, electrocuting targets, knocking them back, and reducing their health. Her power to do so appears weaker than Four's, possibly due to her unstable value.
– Flight/Levitation: Three is able to fly to places and levitate without touching the ground.
– Value alteration: Three can alter her value to those nearby to 3 (including 2.9, 3.1, 3.2 and 3.(1)). This, however, is likely not a conscious or desired choice.

In the present day, Three has locked herself away in a cage, spending years in complete isolation. Even when the other contestants unlocked her cage in "Out Of The Blue", she shut the door herself, most likely wanting to stay away from everyone else to not cause harm. Her sanity seems to have deteriorated due to the time she has spent locked inside of Four.
Three takes on a reclusive, more aggressive and hateful side. Because she is still deeply traumatized and broken because of One, she refuses to leave her cell and she angrily lashes out at Six when she tries to get her out. After being provoked by Six in self-defense, Three furiously attacks Six and the other TPOT contestants around the EXIT, purely out of anger and desperation to make them leave her alone.

Three was shown to be friendly and caring. She constantly did good deeds for those around her, such as putting a band-aid on Five's eye after it gets bruised, trying to fix Nine's skateboard with glue, and protecting Zero from Fourteen. Three also has a habit of observing things around her, an example being when she wrote a note titled "FAILURE" after Eight was shocked when his and Two's stack of cards was knocked over. She also loved science, claiming that meteoritics was one of her "top fifty favorite scientific fields".

Her friendliness is shown especially with One; Three was the first person to want to be One's friend, joining her in sharing the power of the Yoylite. With One, Three shows her energetic side, jolting frantically in One's vicinity after she asks her to walk the rest of the way instead of One having to carry her.

However, she is also shown to be impulsive and bad at keeping promises. Despite One's wishes to keep the Yoylite a secret between the two of them, Three decides to share it with the rest of the Algebraliens, believing it would help all of them. Although she had good intentions, it led to One feeling betrayed and angry, showing that she can unintentionally cause conflict due to her impulsivity.