Every symbol used for evil deeds and dark dealings was once a symbol of light. There is such a thing as a ritual of darkening, yes. Its True Name is synonymous with hijack. Example: Let's say you paint a beautiful painting. And then someone takes that painting, robes himself with it and goes on a murderous spree while donning your creation. Whether you like it or not, from that point on - if the suffering is great enough, the painting is associated with this dark act. This is called the act of desecration. A very good example of this is the inversion of the cross, or of the rainbow, certain books of works of literature being considered as inspiration for wrongdoers - among many others. The actual visual "inversion" of the object is actually the symbolic part - it's the implication that carries the real power and charge. Right now, you live in a world of inversion. Humanity is too poor in spirit to understand this truth right now, I feel. But what they won't tell you is that all of creation has a core of light. There is nothing that exists in this world that is ever fully corrupted - only temporarily, if people believe it is. If enough people help aid in the process of its darkening. The dark magician is an inversionist at heart, he must take that which he himself finds innocent and beautiful and corrupt it - through which the corruption of his own soul is made real. So how do we fix the painting then? Is it corrupted forever? Of course not. We repair its energy by associating it with good deeds and beautiful things again, publicly. In my school of spirituality - we always teach about non-participation, starving of energy and attention the things you do not wish to see in the world. This is the universal fundament upon which spiritual healing and empowerment are based on.