Since I am an Obstetrician, I focused on the Nissian pregnancies and lifecycles. Out of all the vampire races, they are among the few that actually give birth. What drew me to this particular race of vampires was simple: their life cycle is the most unique among any sentient race I have encountered. In order to fully understand this people group, I was forced to look with a non-judgmental point of view. Nissian morality is not Human morality. In my review of their history I was forced to face this fact.
Earlier in their history I found that they procreated with captives. These individuals were usually captured during battle, but some as in the case of a population of humans who were introduced into their world, a large number were found inside their territory and captured. It should be understood that this behavior was mainly due to the fact that population density between the sexes is entirely uneven. To put it simply there are far too many males to far too few females. On average there are 10 males to 1 female. The fact that the majority of those males are out hunting or in the army does not help matters. The truth is high risk behavior can be easily correlated to aggressive tendencies. Our own history of war shows that this is indeed true.
In many accounts I found evidence of subjects recalling as many as three males to one female victim and visa versa. The males are not the only ones who engage in this behavior, but they do seem to be the ones who most benefit from in the present tense. Without going to far into their history I found that males were once considered second class citizens in a female ruled world, centered around a ruling queen. This also might account for their behavior in the transfer of power. It of course does not excuse such actions, but it does help explain it.
.... There is more of this story ...