The most powerful sacrifice that the high priests ever performed was Corinth Sinatra. Forming a powerful divine node and bringing the planes together in harmony.
Corinth Sinatra willingly came down as a sacrifice, to acquire limitless power and to become immortal. However, he did not realize the cost of this power. The cost is to remain here, alive, forever. He has lost what little of himself that was good. Now all he craves is to have company and bring themselves to his own fate. Corinth’s power is unlimited and if someone takes him out of the temple he will still live. For he has gone beyond the mortal plane, and has become truly invincible.
When Corinth sacrificed himself, he connected this area to great divine power creating this node. This evil willing sacrifice however caused the divine energy to be tainted. The only way to cure this evil of the divine powers is by sacrificing a good character to counteract the evil from the sacrifice performed ages ago.