You must obatain 4 drops to get the Ring of the Shissar which is also a key to the Emperor's Chamber. Everyone in your raid must have the key to get into the Emperor's Chamber. It is highly advised that you bring a rouge with a lockpick skill of 210+ along. Some of the creatures can spawn behind a locked door from time to time.

Items needed:
Taskmaster's Pouch
Zazuzh's Idol
Zeruzsh's Ring
Ssraeshzian Insignia

Taskmaster's Pouch drops off of the following creatures in the basement of the temple:
Taskmaster Kavamezh
Taskmaster Keuzozh
Taskmaster Mikazha
Taskmaster Revan`Kezh
Taskmaster Vezhkah
Taskmaster Zerumaz
Taskmaster Zhe`Vozh

Zazushs Idol drops off of Commander Zazuzh a First floor mob spawn, seems any snake can be his place holder.

Zeruzsh's Ring is found on Commander Zherozsh on the second floor. He is on a 2 hours spawn cycle.

Ssraeshzian Insignia is found on on the third floor of the emple on the following mobs:
Arbiter Korazhk
Advisor Zekuzh
General Kizuhx

Once you have all 4 items combine the ring, idol and insignia in the taskmasters pouch and you will have the Ring of the Shissar