If you had turned the Leader's belt in to Ostap, then your current goal would show to collect the leather and metal.
Defeating the Kretch Leader and his army of kretches is all but easy. Once you enter the room you will have little time to hunt down the Kretch Leader and attack him. If you stall for too long you will be attacked by one of his guards and then the fun will start. In total there are 40+ Kretches at this area and it quite possible that you will have to fight everyone of the kretches in the Barracks. If you didnt manage to attack the Leader when you first entered there is a great possibility he will join your fight in due time. This quest is possible alone granted you bring an army of summons to back you up. But to cut the costs try to find someone who also needs the kretch leader and make a group. Its just a straight brawl fight and the strongest will prevail. If you lose you can come back and try again. During the duration of the instance any kretches you did kill will not respawn. You will encounter the following mobs in the Barracks:
Kretch Leader [5] - 700 hp
Kretch Sentinel [4] - 451 hp
Kretch Guard [3] - 138 hp
Note: It is possible to kill the Kretch Leader with out being jumped, or attacked by an entire army.
Contributed By: Moonwalker from Mentor's website. https://sites.google.com/site/info4wod/i…ches-lair-guide