This trophy guide is for The Ultimate Sacrifice which requires you to obtain the Skull of Nan Sapwe.
You're going to need to unlock the majority of the map, which includes the following areas:
-Starting area (opened by default)
-Area with ritual alter containing the 4 skulls (To the right of spawn area)
-Area to the left of the map with the plane propeller traps
-The docks
-Division 9 research lab located at the back of the bunker (Where you build the KT-4)
-Both Labs A and B to obtain power and enter the bunkerWhat you must do is grab a skull, see the symbol written on its forehead and then cross reference its symbol with the one marked on 4 alters throughout the map. The symbols are written in Apothican and can easily be remembered by how many symbols are written in a row on the head.
Example:
XXX = 3
XXX = 3 I would then refer to this alter/symbol as 3,3
xxx = 3
xx = 2
x = 1 I would then refer to this alter/symbol as 3,2,1
This is easier represented in game, or in video format which I have included at the bottom of this guide.
The four alters can be found the these locations:
-Starting area
-Area with Airplane Propeller Traps
-The Docks
-Science Lab you obtain KT-4 inSimply grab the proper skull that corresponds with the alter you've chosen, or, grab a random skull and then find the proper alter and place the skull within it.
You will then have the defend the alter from constant spawning zombies. They have a green mist exuding from them and they won't attack you, they seek only to destroy the alter with the skull.
Be careful not to kill your last non-ritual zombie as it will end the round, whereas doing rituals at the beginning of new rounds can be quite challenging.
Once you've completed the ritual, the skull will no longer be reddish coloured, and will be cleansed. Bring it back to the initial alter and place it back in its location.
Rinse and Repeat for the remaining 3 skulls.
Note: Be careful however, as at any point Thrashers and Spiders can spawn in during a ritual and they will seek to kill you, not the skull.Once all 4 skulls have been cleansed and placed back in the alter the tree trunk on the ground beside the alter will move out of the way allowing you to enter an underground temple.
When you are prepared, begin the ritual by holding
on the Skull of Nan Sapwe. This will cause Keepers to spawn in. You must kill them, as their souls are required to charge the skull.
Once the keepers have stopped spawning in you may pick up the Skull of Nan Sapwe, earn your trophy, and kill some zombies with it.
Here is a video by MrRoflWaffles to help visualize my trophy guide