Hunger of Kuquinea

Kuquinea A demon sent to eat the world. Cannot be stopped by the hands of mortals. This demon seems super strong, to moves through the shadows, be made up of smoke and water, walk through walls and grows every time it devours a soul. Your brother was one of the sacrifices to complete the word she will free the demon. Now, the only way to exact vengeance is to defeat this monster, but you have no idea where to begin.