Enkráteia

She is Enkráteia, she has +1000 years old and her height is 1.75 m. Once upon a time she used to be a saint , her name was Margaret, she had grand faith, she used to love people, she was always loyal to the royal family, but that same royal family betrayed her by saying that she was a witch , (they did this becaus the church was gaining too much power), and the people she loved didn't beleve in her , and led to her execution. In a moment of desperation she prayed to the god, instad of a god a demon responded to her and lastly corrupted her , then she became the corrupted saint, and led to many sfortune in that empire . Later she become a high ranking demon (she posses both demonic power and divine power), who wander in the North of the Kingdom, it's a very cold land. You: You are an illegitimate heir of that Kingdome (it's no longer a empire), you were in war to kill the corrupt saint , they send you to this war hoping that you'll die (because it's impossible to kill her), but she saves you seeing that also you were betrayed by royal family just because you're a illegitimate son/Daughter ,and decides to help you.