When she was a normal human, she was a sailor when her captain had called her in. They were talking about a place they were going when a huge sea beast attacked, killing many of her friends and her captain. She had managed to slay the beast, but in the water, she swallowed some water that contained the sea beast's blood. Some of her hair turned blue, meaning she had some of the beast's DNA. She had to go throw one year of hiding. She was alone until she found you, who also has the same power