During the "Key to Corruption" task you have to do a turn in to him. When we did the turn in it looked like he ate the parts (after spending 3+ hours collecting them).
After 3 or 4 minutes he continued and became aggressive and we had to kill him. Nothing assisted him. We drug him right through the middle of the orc camp (accidentally) and halfway around the zone before finding a place to kill him. He is snareable and rootable and a piece of cake compared to the other four things you have to kill in this mission.