Ferassin root serum
Serum concocted from the native Ferassin root which grows in the 100-square mile wilderness on Zaddik's planet. For many years Zaddik developed the serum in the hopes that it would quench his adopted daughter, Ellia's, thirst to suck the life out of humanoids.
Zaddik instructed her to eventually make the serum herself, insisting that the leaves must be dried and finely grounded up. Distillation was an important step to remove the toxins from the root (otherwise the serum could send her into paralytic shock).
Eventually Ellia told Zaddik that his serum never worked, that while the other Wraith was out hunting she too would go out and find prey.
Instinct - Ellia continues to make the serum for herself, knowing good and well that it has no effect.