Hub 5: Necropolis (map)

''Within the halls of the dead, your former masters await you. In the end, you must emerge victorious or all your struggles will have been for naught.''

Walkthrough
OK...so you've beaten two Heresiarchs, a dead dragon, and tons of monsters. Now you have come to a dark place with thunder cracking...of course Korax shows up AGAIN but this time asks you if "you are strong enough to face your masters." You'll find out what this means later on. Take caution though, because what is behind the "illusion wall" is a cemetery and there are many new monsters called reivers (half-bodies, dead spirits) and they are annoying... and be careful because they come out of the ground too...freaky. Anyway, if you want, you can travel around the cemetery and kill off all the ghosts (there are lots, but once you've killed most they stop appearing) so you won't have problems later on. If you want, go to the far side of the cemetery and go into an open portal which will lead you to the secret level, The Vivarium. If you enter any of the tombs before this, forget that you'll ever get passed the barred door...

So go into the tombs and after you're done with them all, take the relics you took from your masters and open the doors from where you started and that'll lead you to Korax who you'll have to kill to win the game.

Bugs
Not technically a game affecting bug as HeXen never displays a kill percentage: there are three dormant Reivers on the map that are never activated.