BLOOD MOON VAMPIR
It is known that during the total lunar eclipse that takes place twice a year when the moon turns red, a Vampir's strength increases tenfold. What is even more special than that is Vampir children born under the blood moon. It is a miraculous night that affects both Silverbloods and Redbloods.
If Silverblood Vampir give birth to a child under the blood moon, their children may be born a Redblood. Their strength would be just as powerful as any regular Redblood and possess a Redblood ability. For the Redbloods born under a blood moon, their abilities are stronger than other Redbloods. Both types of Vampir, when born under a blood moon, may also have extended lives (by 20-40 years more) and an even slower aging process than other Vampir once they hit adulthood.
There are some drawbacks, however:
Vampir who give birth under the Red Moon are racked with pain. If they do not die during or before childbirth, then they suffer long-term effects after childbirth throughout their lives, mentally and/or physically. It is said to be because the baby is draining them of their strength. Most Silverblood Vampir, because they are naturally already weaker than Redbloods, die.
Vampir born under the blood moon need to feed on human (Magi) blood every 3 months (as that is how long they can go without it before they start reverting to monstrous instincts). No other species' blood will do; it will only hold them over for a bit longer.
Most notably, under every blood moon, their demeanor changes into what the classic sadistic type of vampires in literature. They are not themselves, or perhaps they are more themselves than ever.