Once you reach the top of the tower you'll fight the Dark Elf again.
This is the same as his last appearance. He uses more magic, but fights just the same. When he's dead continue to the right and up the stairs, then to the right and through the skull doors to fight Deimos. But first Deimos sends out the last of his foes.
Deimos says "dissolve" and the floor turns to mud. Two Mud Golems rise from the mud and attack. Golems are animated but not reanimated, so Turn Undead won't work on them. They don't breathe, so Cloud Kill won't harm them either. If you have any Fire Balls or Lightning left (either spells or rings) you should use them now, because Deimos is impervious to them. Magic Missile and Sticks to Snakes also work very poorly against him (but they do work).
The Mud Golems are slow, but powerful. Unlike all other foes they are unable to be stunned or knocked down. This means when they start an attack they can keep going no matter how much you hurt them. The best way is to use spells, items or faster attacks. If you do a back attack (jump over their head while they perform an attack, then turn and slash while in the air) you can get in a few hits before they finish their attack and are able to turn around.
Now and then the Golems disappear into the floor and only their head and hands show through. It's difficult to hit them like this, so if you avoid them they'll just come back up again. Eventually you'll defeat both of them. Deimos will say "harden" (which the floor does). After standard declarations of dancing on your graves he fights you himself.
Deimos hovers around, casting spells and swinging his staff. He also has some spells of his own. You can tell he is about to cast a spell when a large skull appears in front of him. If you harm him as soon as you see the skull you'll cancel the spell.
- Mirror Image: flickering duplicates appear. These attack in synch with him, and deal real damage. Attacking an image will dispel it, but does no damage to the real Deimos.
- Fire Shield: he surrounds himself with a cylinder of flame. Just back away until it dispels.
- Meteor Storm: this is like Fire Ball. Four or eight meteors start falling. Most are locked onto players, but others just fall randomly.
- Teleport: he reappears in a random location.
- Fireball: same as the Elf's but can be aimed anywhere.
- Lightning Bolt: same as the Elf's.
- undead flash: Deimos makes the screen flash (knocking everyone down, but doing no damage) and causes Ghouls to appear. He only uses this a few times.
Deimos uses his staff when you line up with him to the left or right. If you stay out of alignment until the last possible moment you should be able to nick him with the very limit of your attacks before he reacts. If you don't get the distance right he'll hurt you.
Eventually you'll defeat him, and he starts to dissolve.
"No! This is impossible! I am destined to rule, to conquer! How could I have been beaten by whelps like you?"