In order to complete what players wrote
HERE I will just write straight forward info.
Phantom Corpse - After defeat you will have the option to unlick either Singing or Silent room.
Singing room - Chess drop for cuirass/cuisses
Silent room - Twilight/Mammoth/Executioner Cuisses
Revrat - 50 HoU rep up to 500. After defeat you will have the option to unlick either Singing or Silent room.
Singing room - Chess drop for weapon
SIlent room - Twilight/Mammoth/Executioner Cuirass
Galmakhar - 50 HoU rep up to 1000. After defeat you will have the option to unlick either Singing or Silent room. And you will also receive Galmakhar's helmet (broken) that can be used to create Twilight/Mammoth/Executioner bracers from the quest "Galmakhar's helmet" available at Shiko from lvl 4, or you can just break the helmet for 1 Efril.
Singing room - Chess for boors/shirt
Silent room - Twilight/Mammoth/Executioner weapon
Zermerkh - 50 HoU rep up to 1000. After defeat you will have the option to unlick either Singing or Silent room.
Singing room - Chess for pauldrones/bracers
Silent room - Twilight/Mammoth/Executioner boots
Lingraonz - 50 HoU rep up to 1500. 5 pcs Efril to each member of the group that participated in the fight. After defeat you will have the option to unlick either Singing or Silent room. You will also receive Lingraonz Crown (for creating a green helmet after quest available from lvl 5 at Shiko) or Enchanted Lingraonz Crown (for creating blue helmet). You can also break the crowns to receive efril.
Singing room - Chess for helmet
Silent room - Twilight/Mammoth/Executioner pauldrones
*Note that if you need to transfer any chess pcs or green item to someone else that you they must be in the group before you unlock the room and receive the item.
Bosses availability according to the lvl:
lvl 5 and bellow - All bosses can be killed during 1 instance.
lvl 6 - Revrat, Galmakhar, Zermerkh, Lingraonz
lvl 7 - Galmakhar, Zermerkh, Lingraonz
lvl 8 - Zermerkh, Lingraonz
lvl 9 - Lingraonz
lvl 10 - No boss will give drop
*info: How to reach Lingraonz:
If you are planning on killing Lingraonz you must reach Revrat's room first. There you will find a lever as shown bellow
[img]http://www.paladiny.ru/cache_image.php?T=0&I=http%3A%2F%2Fimg179.imageshack.us%2Fimg179%2F2488%2F17690517se2.jpg[/img]
you must pull the lever, you can do it more than once to ensure that you really opened it.
If you are reputation hunter there is more availabilities than just doors and bosses. In every stash room marked on the instance map with Chest you will find
which will bring you 10 HoU rep up to 1300. However in this stash rooms you can find a hidden place that can bring you as per the following:
Lingraonz Curse - Duration 30 minutes. Removes 3 life points from you every 3 seconds.
Healing Bless - Duration 15 minutes. Increase your life with 20 heal points.
Master's Bless - Duration 15 minutes. Increase yout Intuition, Agiliry and Protection with 15 points.
You can also find various elixirs, undead chests, pile of papers and many other things a regular stash can drop.
*Note that only 1 member can receive anything from 1 room's stash.
Hidden passages.
Whenever you reach either's boss room you will see there "hidden passage". When you click there you will be automaticaly transferred to the entrance room wth portraits. Opening the passage from inside boss room will allow your next group members to reach this location without waiting transfer times. They will just need to click on the portrait of the boss' room you just oppened.
This is in general. Feel free to add what wasn't added in the topic I mentioned before, or here in this topic.