Posses the Power of the Devil

Blace the bones of the purist hearts on the ground of a cemitary (must be an open ground). And then place the evilest bones on the purest bones and make sure you can do something truely evil (like pray only for the devil/wear the pentagram). Take a random animal that means truely and kill it and give it to the devils power as a transfer. Take the blood from a loving person and pour it on to the animal to feed the powers and say: "From hell to heaven I call upon a power of great evil and dispute. I call the power of the devil to make me powerful too".