We're twins but we walk a different path.
We're not the same, and would never be.
We're stranger, we always will be.
Always remember this, sister.
Us two could never be considered as twins.
(Vampire Knight x Diabolik Lovers)
X Reader
You the reader got to experience different stories from each character.
My interpretation might be different from yours, and this is what I think their characters are.
!!! MATURE CONTENT IS VERY LIKELY, READ IT AT YOUR OWN RISK !!!