The Corrupted Priest - Act 2 Side Quest
Start Location: Temple of Seti
Quest Location: Meretseger Ridge
Objective: Defeat Neb-kemi inside of the cave on Meretseger Ridge
The Corrupted Priest is the final side quest available to you in Act 2 and begins by speaking with Amen-nahte at the Temple of Seti (pictured above). For this quest you will need to find Neb-Kemi inside of the mysterious Tomb on Meretseger Ridge and kill him.
You'll find the tomb on Meretseger Ridge a tad bit northeast of town. Instead of following the path up into the mountains and to the north you'll want to continue east to a plateau which is where you'll find this tomb. Use my screenshot below for better map directions.
Once inside of the tomb you'll find Neb-kemi, the named that you're here to kill in the back. It's a rather small tomb and Neb-kemi only has a few skeleton and construct guards with him.