Shadows of History

Getting the key
To start the quest, speak with Antheros. He will ask you if you want to take the ultimate test. Say yes. Then you start the quest. First, he ask you to retrieve the key of truths in the Lumbridge Swamp. There will be a tunnel called Lumbridge Abyss. There will be level 60 Saradomin guards. Kill them with with the dragon spear (p++) until you get a key. A door will appear. Use the key and you will be teleported to a room with Zamorak warriors. Kill them with the Guthix bow. You must kill all Zamorak warriors less than an 45 minutes or else you will not be able to hit anything on them until you die or teleport away. Once you kill all of them, a chest will appear. open the chest to receive the key of truths. once you give it to him, a portal will appear. Go through.

Getting the Scroll of History
Once you go through the portal talk to a Guthix Archer. He will request to kill a dangerous dragon called Dransco. Go directly north to kill Dransco. You must have a Guthix bow with a Guthix platebody on to damage Dransco. Once you kill him, talk to one of the Guthix archers. He will reward you with the Scroll of History.

Learning the truths
Read the scroll. It will say:

"Years have past from the third century. And things Are going out of hand. Evil. War. And yet the word still lives. But every day somebody gets killed. So I have created something more powerful than any beast known. It will destroy Anything provoking it. I stand, please have harmony."

Go to the portal you came in and show Antheros what you have found. After he reads it, he will become agitated and say that the "beast" is called Guthix's Shadow. After he tells you that, you suddenly get teleport to the realm of Guthix. Guthix will appear and say "Are you ready for truths? You have learned enough. Now learn the rest." Then you will see a cutscene of Guthix weeping over the destroyed land. After all his anger, he does this magic that creates a green-armored version of a corporeal beast level 40713, then rampaging through the colonies that follow Saradomin, Zamorak, Armadyl, and Bandos, using complex spells and slashing away buildings and retaliating guards. Then the cutscene ends. Guthix will say, "Make your choices wisely." then you get teleported back to the room with Antheros and complete the quest.

Rewards

 * 500,000 coins