Chrome King Gallywix in Liberation of Undermine drops a curio on all difficulties that you can turn in for 1 Class Set piece.
Curio Vendor Location
The vendor is Kari Bridgeblaster. She is located on the second floor of the Incontinental Hotel. Bring the 
Excessively Bejeweled Curio to her to exchange it for 1 Class Set piece from the Liberation of Undermine raid.
Curio Item Levels
The item level of your Class Set piece depends on the difficulty you defeat Gallywix on, ranging from Item Level 626 in Raid Finder to 668 in Mythic.
- Excessively Bejeweled Curio (Raid Finder) – Item Level 626-629
- Excessively Bejeweled Curio (Normal difficulty) – Item Level 639-642
- Excessively Bejeweled Curio (Heroic difficulty) – Item Level 652-655
- Excessively Bejeweled Curio (Mythic difficulty) – Item Level 665-668
