Hub 5: Dark Crucible

Dark Crucible is the final level in Hexen. It is where you face Korax himself, along with an army of his minions. Although it is part of the Necropolis hub, you cannot return to any of the other levels once you have entered it.

Walkthrough
You begin on one side of a bridge. Cross the bridge (while avoiding the instant-death fall past the edges) and open the door. Inside, there are three switches: one to your immediate left, and two on the walls near the door. Begin by pressing both switches nearest to the door, then the switch you saw when you entered the room. A random type of mana, possibly even a Krater of Might, will appear next to the two switches near the doors. Doing this every fifth time after the first (ie, 6th, 11th, etc) will cause four Dark Bishops to appear. If you feel you can kill them without being hurt (as you'll need to keep up your strength for Korax), go ahead and continue to collect mana until you are well-stocked. Then, open the large door.

You will find yourself in a very large room, housing a few Discs of Repulsion on either side, and two Kraters of Might. There are also a few circular crushers in this room: avoid them at all costs. There are three doors here: one large one in the back, and two barrier-doors on the left and right. Korax is at the back and center of the room, and he greets you with a barrage of attacks. Attack him until he teleports away; when he does this, the two barriers on either side of the room will open up, revealing no less than sixteen Ettins in each room, for a total of 32. These small rooms hold four Crystal Vials and a Krater of Might each. Kill the Ettins, and the barriers behind the rooms that housed them will open as well, leaving you to deal with 32 Centaurs. Kill them as well, and the door in the back of the room will open.

The second (and final) room is about as large as the first, with two barrier-doors on the left and right sides of the room. There are stairs leading to the back of the room, where Korax himself resides initially. Beware of the two circular crushers as in the first room. Defeat him and a portal will appear at the back of the room. Enter it and watch the ending sequence.

Congratulations, you just beat Hexen.

Defeating Korax
Korax is no laughing matter: with a boastable amount of HP and an array of traps and attacks, you may as well use every single item at your disposal.

The First Room
Here, you will get used to Korax's most significant attack: his six-shooter. Each of his arms will shoot out a random blast, whether it be Chaos Serpent fireballs, Brown Chaos Serpent poisonballs, Afrit fireballs, Stalker acid blasts, Reiver spikebombs, or a blue attack (unique to Korax). Regardless of the attack, being hit by all six at once typically causes death, even with full health. Fortunately, the attacks are slow and predictable, so they are easily dodged.

The tricky part of battling Korax in either room deals with the various traps he has laid out. In the first room, once he releases a blut flash of lightning from one of his hands, any one of these things will occur:
 * Spikes in the center of the room will rise quickly, starting from the front and moving to the back. After about five seconds, they will lower.
 * A majority of the floor will turn to lava. The only place where you are safe is the along the middle of the room, so it is wise to stay near there at all times.
 * Spikebomb traps will come from the ceiling, randomly spewing spikebombs all across the room. These don't hurt nearly as much as Korax does, so avoiding them is second to avoiding him.

The Second Room
By now, Korax has already taken a considerable amount of damage from your first encounter with him. In addition to the details mentioned in the first room, he can also do the following:
 * Open the barrier-doors on either side of the room. The first room will reveal 16 Chaos Serpents in each of the rooms, and the second room will free 16 Dark Bishops.  As it usually takes a while for him to do this, it is recommended to kill Korax as soon as possible, for this will make the battle considerably harder.
 * Teleport around. He can teleport to five different places: to the back-left corner of the room, the back-right corner of the room, the back-left side of the first room, the back-right side of the first room, and his original position.  He will always teleport in this order, although he can sometimes teleport in rapid succession.  Learn the path well.
 * Summon Ghost creatures. These Ghost creatures will either be Slaughtars, Chaos Serpents, or Brown Chaos Serpents; they will not have corpses when they die.  Compared to the rooms with literally hordes of monsters, they are only a little nuisance.

Class Suggestions

 * The Fighter will have the most trouble, as Korax is very difficult to attack close-up: use Quietus from a medium distance for best results. If you wish to attack from a melee distance, it is highly recommended to expend an Icon of the Defender before doing so.
 * The Cleric has it fairly easy with his Wraithverge, although you may want to conserve mana for the time being: Firestorm will take a while but gets the job done.
 * The Mage can use his Arc of Death to lock down Korax for a majority of the time, making it difficult for him to attack or activate traps: Bloodscourge is also a good option.

As it was said before, you should use all the items you have: you're given at least four Kraters of Might in this level alone, and likely have a few Icon of the Defenders left waiting for another Heresiarch battle. In the Second Room, it is imperative that Korax is killed before he unleashes the armies of difficult monsters, as it will make your job much more difficult.