When you kill the High Council of Zakarum and shatter the Compelling Orb, Zealots will run away in fear when you approach. They appear in several versions: Zakarumite, Faithful and Zealot. On Hell difficulty, Zakarumites are immune to Fire, Faithful to Cold and Zealots to Lightning. Some of the Zealots are seen also in Act V in the three corrupted halls of Nihlathak.