In WoW Classic, Warlocks are able to access several unique class quests. Any Warlock can start the Level 50 Warlock quest chain, regardless of race or Faction, and completing this chain allows you to choose one of the following items as a reward:
- Soul Harvester
- Abyss Shard
- Robe of Servitude
An Imp's Request
To start the final Warlock class quest, simply talk to any Warlock Trainer in any Capital City. They will offer you the following quest:
- An Imp's Request
To finish this quest you'll need to bring a Felcloth to Impsy in Felwood.
Felcloth can be dropped by most demons in the game, from Dire Maul, Felwood,to Azshara.
You can also buy Felcloth at the Auction House, however it is quite valuable and may cost you quite a bit of gold.
After completing this mission, Impsy will give you your next class quest:
- The Wrong Stuff
You'll be asked to gather the following materials:
- 10x Rotting Wood dropped by Irontree Wanderers, Irontree Stompers and Withered Protectors
- 4x Bloodvenom Essence dropped by Tainted Ooze
After bringing these marterials to Impsy he will offer you your final class quest:
- Trolls of a Feather
You'll need to collect 3 different pairs of feathers from Sunken Temple, in the Swamp of Sorrows:
- Amber Voodoo Feather on Gasher and Zul'lor
- Blue Voodoo Feather on Hukku and Mijan
- Green Voodoo Feather on Loro and Zolo
These Troll mini-bosses can be found in the Sanctuary, on small balconies overlooking the central area you pass through when you first enter the temple. For this quest, all you need to do is create a 5-man group, work your way through the instance, kill these creatures and loot the quest items from their corpses, then finally return to Impsy and turn in the quest.
Impsy will then be waiting for you with the following rewards:
- Soul Harvester
- Abyss Shard
- Robe of Servitude
Without a doubt, you should choose the Robe of Servitude, as it is very powerful. The other two items are very trivial, while this robe is unrivalled on your way to Level 60.