The Maze Engine expansion will introduce new enchantments and campaign currency aimed at giving players a helping hand against the demon spawn infesting the new areas. Quests to assist King Bruenor Battlehammer against Baphomet in his siege on Gauntlgrym (I am not making any of these words up, mind) will grant rewards spanning from Dwarven Battlerager companions and fashion gear to mount insignia and your choice of shards, seals, and tomes.
Completing the campaign itself will award new boons and part of a three-piece artifact set, while poking your nose into Castle Never and maybe doing something useful in there will pave the way for you to collect ruined and shattered items as well as snag a chance at “6 new Underdark Rings, including the Ring of Orcus, which has a chance to summon an undead servant when you are struck.” Your very own servant!
Check out the complete list of goodies awaiting adventurers.