A demon's Soul

As darkness creeps in the castle of the Evannalines kingdom,a mother gives birth to the two amazing things in her life.She never thought of anything greater than this.A life with her lover and two daughters.
But as someone survives someone also dies.It is to equal balance and tranquility of the world.It is never to be expected as the end of the whole kingdom as the two siblings came but it is as said of the prophecy.
A prophecy that will never come to an end,and a prophecy as long as time itself.
Hunters came to the castle rallying their forces,their goal to end the empire of the most powerful and ruthless beings of all.And also to take revenge of the human who was took from them and made as the queen of all beings.'The queen of demons itself,Queen Lacrymosa'...
She was most beloved of all and respected by hunters when she was a little girl but as time passes by a demon fell inlove with her.She never expected as their first night together would be the last of her mortality.
She deeply fell inlove with him and as their bond would never let them stay away from each other.She would always go to his kingdom and leave her own cotterie on its own.
But the hunters got curious of her and as 3 months had past and she never went back again.
They tracked her,searched everywhere for they're beloved young lady.But only found her pregnant with two children and their enemy as the father.
They planned on taking revenge on her and the whole family.That they ended up killing all those who are ruled by him and are part of the kingdom.
The two lovers got aware of the hunters plan and as they can't leave the castle because of the danger they called a witch and ordered her when the day has come of the birth of their childs.They will agree on letting the witch take both of the twin's souls and take it to somewhere they could be safe.Away from the war and chaos happening between the two realm.
So the day has come,the castle was burned down and the king and queen was nowhere to be found.