Unmixed Malevolentia

The carrow sisters.
Their beauty is beyond imaginable, and they know it.
You'd think with such beauty they're the sun you dream of when summer comes into light.
Unfortunate for some, that is far from it. They're twisted, dark, and fond over the colour of crimson on bare skin.

Theodore and Mattheo.
Handsome as the brightest days you enjoy.
However, with that, their brains are a forest of spiralling manipulation and cunning torture chambers.
The drip of red liquid from a knife holds the joy you would feel over a passed exam.

The four of them together were trained like this since childhood, it's all they know.
However, when they finally join each other, locked away in an abandoned mansion passed down to them with barriers only they can unsecured.
The enemies they were brought up to be against finally switches.

What will come of this?

Enemies to lovers-slow burn - Mattheo riddle