My attitude toward this is that it is similar to human sacrifice -
certain rituals such as cannabilism, headtaking, or trophy taking,
undertaken under restricted circumstances by practioners of certain
religions (such as those with links to Ana Gor) are permissable. By
acting in line with these covenants the worshipper is protected from
becoming a krjalki, ogre, broo etc. Acting outside these covenants is
not protected. Taking an great and noted enemies head is permissable,
building a pyramid of shepherd's heads outside your hearth door is
not. Of course this does not protect you from the wrath of your the
victim's kin, but that's the risk you take.
The chaotic cults differ by their attitude to these acts; and its
your attitude when performing them that counts.