Bosses and strategy
He summons Rain Elementals, teleports himself all around the place and uses spells to slow all the players down. His spells drain the energy from energy-users and slow down the casting. Kill the Elementals quickly, or else there will be lot of them.
Depending on your faction, you will need to defeat one of the leaders. In case of Voisvet, you will be fighting not only him, but also Loyal Worshipper. They are supporting each other with heal and have the skills of Healer archetype - Blind, Heavenly Smite etc. If you kill worshipper near Voisvet, he will instantly ressurect him. Tactics is simple - separate them with main tank tanking Voisvet, kill the worshipper in different room and then finish off Voisvet.
- Nomarkh Khatire and Hurken the Controller
It is also 'Dual boss' so the strategy is very similar. If Khatire and Hurken are in the same room they heal and Khatire changes the target often and knock them out what makes him very hard to tank. Separate the Demon and Khatire as soon as possible, Khatire will be very weak then. But beware, the Demon hits a lot harder then Worshipper. Kill them one by one.
As soon as you step into the room, Nefer Ur or Voisvet Belov appears and starts to fight Gorluxor. You can't target Gorluxor at the beginning since he has a shield around him, your main role will be to protect your 'hero'. Let the healer heal Nefer or Voisvet all the time and the rest of the group kill the waves of enemies trying to kill him. When Gorluxor's health drops to 20%, he will lose the shield and you can kill him. If your hero dies, the shield around Gorluxor will still drop at 20% HP as he loses life at a slow rate. This allows a party without a direct healer to still complete the encounter, though with the possibility of taking longer.
The boss appears as soon as you enter the last chamber with Tensess' soul. This is a multiboss fight, it starts with many weak demons and will continue in waves. For every two you kill, one stronger one spawns, however it's easier to deal with them. Each subsequent spawn has about 2x HP and 50% more damage (except for the boss). If you have some mana/hp issues and you have the last spawn there, you can either CC him or tank him and let mana-users use salvation. A good scout can kite up to 3 mobs indefinitely, a mage can freeze the last mob, or a paladin can flip barriers as an example. Once everyone is ready, kill the last mob to spawn the boss. This is a tank and spank boss, however he hits relatively hard.