Heir to the shadows

This is part 2 of heir to the darkness
spoiler for those who haven't read the first part!!!

After losing everything she had, Cassiopeia comes back to Hogwarts with a sole motto to revenge her loved ones, as the colour of the sky darkens with days that fall ahead she embraces the dark magic that follows through her veins.
Can she protect Theodore and Draco as they fall prey to her father's hunger to expand his pureblood fanaticism to the young generation

This story is AU where the dark side is absurdly strong I won't be following the original story path as from here things get different.