First off head to Plane of Knowledge, and talk to Gilgamesh. Pick up the task from him (for tracking the quest items/locations).
You will need 8 items in total to get your new epic weapon.
You can obtain these books by slaughtering everything you see in the appropriate zone.
Next you will need:
This is a Tier 6 fight.
Assuming this is a Tier 6 fight as well.