You can also get this in Orobas Fjords later in the game: each of the four bosses of the flying fortresses has a piece of the Ulthring Armor set. By mind-reading each boss before you start fighting them, you'll automatically get the armor piece they're carrying once the battle is over.
You have to mind read all of them, otherwise you won't get the set. It will cost around 3600 XP to mind read each boss. When the boss starts talking to you, press X to mind read.
- Kali has the Helmet
- Xanlosch has the Gauntlets
- Stone has the Cuirass
- Raze has the Leggings
Make sure you're at around Level 30 before taking these characters on. The first three fortresses are marked by glowing gates on the cliff sides, with the last one at the very end of the winding fjord. When you're at the fortresses look around for glowing green portals while you're on foot, which will take you to each boss' chamber.
If you mind-read each boss, the achievement will unlock as soon as you gather the fourth armor piece from the dropped loot bag. You'll also get the "Castle Crasher" achievement once the fourth boss has been defeated.