Soon after Deismaar, when newly blooded scions from the two sides met in battle for the first time, a strange discovery was made. If two scions met in battle, and one perished, it was possible for the victor to claim a portion of his slain foe’s divine energy and thus become all the stronger. The awnshegh known as the Spider was among the first to discover this ability as he fought to become leader of one of the surviving goblin tribes; this Usurpation of the other scion’s power help turn him into the corrupt being that exists today. Since that day, thousands of other scions have fought to claim other’s birthrights, drawing their enemies into traps or even challenging them outright, for usurpation of enemy’s divine bloodline remains one of the easiest ways to increase one's own power.

However, because the scions divine essence is contained in his blood, this usurpation can only occur if a scion dies in a violent manner and his blood is literally spilt. If a blooded character dies non-violently, by poison, or a spell that doesn’t result in the spilling of blood, then the divine essence of their bloodline passes with them, either to their heir or to into the land itself if they had not designated a heir. However, if a scion’s blood is spilt as a result of his death in hand-to-hand combat, or another way that makes the victims blood to splatter on those/the one he fought, then the divine essence of his or her birthright is released in a burst of immediate power.

For a weak bloodline (tainted), the release of a dieing scion's divine essence may only produce a slight tingling perceptible only to those in the immediate area of effect. The slaying of a scion of a minor bloodline might produce more noticeable effects like crackling static discharge, gusts of wind, etc.
The violent death of a scion with a bloodline of Major strength can produce affects up to a storm of crackling energy and violent winds.
And lastly the effects associated with the slaying of a scion of a Great bloodline may be visible and/or felt for miles.

People, animals, and on very rare occasions, even objects in the immediate area of a scion's violent death may absorb a portion of the scion's divine essence. Any blooded character within the radius of the effect may absorb some of the released divine power within this burst, however how much is absorbed will depend on the strength of the receiving scion’s bloodline. A scion with a particularly weak bloodline will only be able to absorb a small portion of the released regency. A scion of a very strong bloodline, on the other hand, may find the released energy does very little to enhance their bloodline strength.

While this bloodline usurpation may seem an easy way to increase a scion’s blood power, it does come with its risks. When a scion absorbs the bloodline essence of a scion with a bloodline score higher than his, then he faces the risk of the victim’s bloodline derivation effectively overwhelming his own. It is actually possible for a scion’s bloodline derivation to change as the new, more powerful bloodline grounds itself in the slayer’s body. This usually only occurs when the recipient recives a significat increase in bloodline (with significant being measured out of how much he had before compared to the increase). If this happens, then the scion makes a contested check between his old bloodline derivasion and the possible new. In the case of the new bloodline being Azrais, the corrupting influence of the dark god’s bloodline is particularly difficult to resist, and that side gets a bonus. There is also said that some awnsheglien or Azrai bloodlines are even more corrupting then others, and those would gain even a further small bonus. This is one of the reasons why Azrai’s bloodline is still so prevalent in Cerilia; many a scion has slain an Awnshegh only to discover his has become corrupted by Azrai's foul taint. If a scion’s bloodline derivation changes, then any blood abilities he possessed that are not available to his new bloodline derivation might be immidiatly lost, and new abilities permitted by the new derivation replaces them. Or this might happen over time. And then again, there is even reports that some fledling awnsheglien has manifested powers that mimics their old perfectly...

Bloodtheft and how sociatly views it
Bloodtheft have from the very start been looked down on with very stern eyes in the empire. Haelyn himself told his priests in the first century that he "Did Not Like That Kind of Practice At All". Because of it the Imperial Temple made sure that the Empire opposed such practice. When the Empire fell through, and Anuire has its on and off civil war for over 80 years, such practices flaired up greatly, and with the Churches divided like no time before or since, neither where there any unified "divine" resistance to it.

So when the new Archduke of Boeruine and the Prince of Avanil at that time finally managed to sit down and make peace between them, and the civil wars ended so that the old tradition of the Sword and Crown finally once more where picked up, now with (as it would be agreed that year) even much wider mandate, the Council of Twelve sat down and discussed the issue. It was agreed then and there to go back to how it was while how it was while the Empire was united. That all sides not only oppose bloodtheft, but for the benefit of all, actively work to limit the knowledge of the facts around it. Under the civil wars, people on both sides had hired many unblooded assasins. Of which some seemed to go out of their way to take out as many blooded people as they could find to increase their own power, and further more they got followers whom did as they. This made the blooded nobles realise it would be better that people did not know there where a violent way for unblooded people to take their powers. With 9 votes for, the Council decided between them to remove all written reference to bloodtheft in the history books, and to limit the knowledge of the facts. If people do not know that you can get bloodpowers by killing blooded people, its less likly they would do so was the thought. As decided so it was done.

Today there is very few references to the fact in any book open to the public. Some of the older religious texts do reference them, but they're all on Andu, and their Anuirean copies are somewhat more vague on the subject. And all the major blooded families of course have an oral tradition on how things work. But in Anuire today, there lives several families of minor or tainted bloodlines that no longer know fully on how things work. [To that affect, anyone not of a Major or greater line (or having been so in the last generation), a rank in Knowledge (Bloodlore), or a total of +8 Knowledge (History) would not know about these things unless they've somehow relearned it through experience or been told by someone in the know).