The Heretic is a Main Quest in Assassin’s Creed Origins – The Curse of the Pharaohs DLC. This walkthrough shows how to complete this quest.
Recommended Level: 48
Region: Theban Necropolis
Requirement: having finished Aten Rising
Reward: 10.000 XP
Objectives:
- Find and get Tychon’s ledger
- Find the statue of Amun-Ra
- Reach the tomb of Akhenaten
- Explore the tomb of Akhenaten
- Find your way through the Am-Tuat
- Examine the Guardian Statue
- Destroy the symbol of the Aten
- Destroy the remaining four symbols
- Reach Akhenaten’s throne
- Defeat Akhenaten
This quest starts in the region of the Theban Necropolis. We have to steal a ledger with information in it. The owner Tychon will be located at the port-outpost during daytime. At night he would be at the Temple a bit to the west. He has at least one other guard with him at nearly all times, so taking him out might cause a few follow-up-melee-fights.
Once the area is clear, loot him and take a look at his ledger. The statue of Ra, which Bayek was looking for, is located in the armory of the nearby Temple of Hatshepsut.
The armory can be entered from the right-hand-side through a small opening, as marked below. If you want to have some fun with the mounted crossbow, this would be the chance to get rid of some patrolling enemies. This temple isn’t guarded too well, so you might just go inside directly.
Once jumped inside, the statue of Ra will be located to the right.
Now, we’re off to another adventure in the afterlives, as we have to come face-to-face with Akhenaten and bring him down, to lift a part of the curse. Travel to the Valley of the Kings and enter the tomb. The few guards afterwards can be ignored, just run past them and dive down into the water.
Get back to the surface and take in the eerie-and-beautiful scene of the region Aten. Our first objective is located just to the left of us.
The large sun above shines towards the symbol the small sphinx is holding. Our best bet is to destroy all of them.
Once the first one is destroyed, the other four will appear on the map as well.
If you read the map above like a clock, the location for the one at “four o’clock” has to be entered and exited while diving from the eastern side.
After you have destroyed number five, a new ray of light will form from the sun and point down on the throne of Akhenaten. Looks, like he is ready for us.
He indeed is ready, once we arrive at the scene. This fight which is coming up can take up to ten minutes because you have to dodge 
a lot and time your strikes perfectly.
His blows will always take at least a fifth of your total health, but he also has a chance of killing you instantly.
Just like any other fight, remember that once a complete health bar of yours is depleted, it won’t recharge. So once you have been hit once, immediately back off and wait for your (remaining) health to be fully restored.
He will always do a sequence of about six swings/blows with his sword. Get a feel for it for about a minute and when he looks roughly like below..
..it’s a good chance to set a quick blow or two yourself.
Make use of your special attack 
+ 
once it is ready. If you have some weapons which deal elemental-damage-over-time, make use of them. This way he will lose health, even if you are dodging around. And you will dodge around a lot.
Eventually, you will get him soft after about ten minutes.
Once he is down and this quest is completed, you can talk to Isidora to continue with The Curse of the Pharaohs-Quest (if you completed The Lady of Grace before).
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