Now you can easily read the text on the page. It says: "The blade has slain the master of the lair, His spirit left the coil, yet fate has nets that hold the soul It comes again, ablaze with hate, to fail once more Begone to restful darkness, but its shade is captive still To Sanctuary it’s borne by heroes, the destiny weaves on and on..."
Go to Limbo located in the Sanctuary, and destroy the Leader. Obtain his soul.