By consuming the essence of Die Ewigkeit, you gain several boons:
*A relic of your choice is bound to you. It could be the Spear of Destiny, a famous object, or something more mundane. With this relic you are able to grow stronger by killing beings and consuming their souls for strength. Or you can just grab free-floating ones if they are available. The more souls you have, the stronger you get.
*You are able to advance through all stages, starting with Assiah where you begin, all the way to Atziluth, the greatest expression of this power.
*The various abilities that come with your advancement through the stages are up to you, as long as they fit within the confines of how each power at a stage manifests.
*Any souls you consume won't be used up as fuel like normal, instead being temporarily unavailable while the soul regenerates.
*You know the basics of creating relics to give to other people.