Grey

Aelynn Greyson Song, who will kill you if you use that name, and prefers to go by Grey, is Ren's soulmate. She has a deep blue amulet, which allows her to control water and shadows. She also helps to heal everyone, and during battles either floats on a bubble of water trying to heal everyone, or she hides in a corner, gathering water and shadows for an attack.

Amulet (Blue Amulet)
As said, the blue amulet allows the wearer to manipulate water and shadows. The person can draw on the water from the air and shadows, controlling and shaping the substances.