Aqua used to be op until she made a dumb mistake and ended up with only the power to control wind. She lost her mind in the process and went on a killing spree. When she regained her sanity, she swore to never kill without reason again.
Since she can control the oxygen in the air, she can stop people from breathing or (her favorite) cut them up with her powers.
She's very energetic and loves to run, though she's not very fast.