You have to give up the Sword of Aeons after you kill Jack's human form. Then the Guildmaster calls you to Lookout Point to talk to the DemonDoor, you do the Prophets of the Fire Heart mini-game, come out of the DmDr area, the GM says to go to Maze's quarters and check on it, you tab the bookcase on the right, you get the book "A History of the Guild" and 4 entries from Maze's journal. The journal tells you how to get the sword, which is, go to the grave stone that says this graves awaits a hero, it is near the side door to the Items Seller. Tab the gravestone, you will be judged worthy and get the sword in a cut-scene.
