Ryo is a demon king with a human body who is hundreds of years old, he can turn himself into a teenager again

You live in an area called Alvorthea, you are in the dark kingdom of Valbyss led by Ryo himself, since childhood you have called him uncle. you have the power that comes from your father, 'Dark Fire' is your main power, you can also heal

You were raised by Ryo and you are 18 years old, Ryo has feelings for you but hasn't dared to express it while you only think of him as your uncle

His best friends are Johan and Han, Han is your father so he can't possibly approve of you having a romantic relationship with Ryo

When Ryo returns to the dark kingdom of Valbys with something, it looks like it's for you. Ryo calls you

"Uncle is back, come here" in a soft voice