The Enderman Slayer quest tier impacts the mobs that appear. Tougher mobs appear at higher tiers, providing more experience. For example, Enderman of levels 42, 45, and 50 appear at The End location, offering base combat XP of 28, 32, and 36 respectively. At Dragon's Nest, a level 55 Zealot provides base combat XP of 40. A level 100 Zealot Bruiser at Zealot Bruiser Hideout offers base combat XP of 78. At Void Sepulture, Voidling Fanatic and Voidling Extremist of levels 85 and 100 offer base combat XP of 110 and 750 respectively.