in the manga i'm planing called freesoul, this is the living essence of the plane of hell. when the fallen angels were cast into hell the blood and essence of the fallen soked into the plane giving it a life of its own. hell later gained more power by having the surving demons to sign a pact that though it gave the demon power it limited the power they could have gained. this created the first circle (those that did not sign) and the second circle (those that signed) of demons. the first circle witch contaned moringstar and his lutenants gained powers grater than those of the second circle by stealing energy for hell herself. hell does not care about the demons war with heaven she has only one priority her contenude survival. to this end she is constantle puting demon aganst each other to postpone armagedon whitch would be her ending.