|Mysterious Armor Pieces|
Mysterious Armor Pieces can be only be obtained in the The Shadow Nexus Challenge Mission. It does not drop, but instead appears in the player's inventory at random as a reward after killing a Portal Mage.
Applying a Mysterious Armor Pieces to a hero's armor will upgrade their armor to the hero version of the "Mysterious armor" look. (Note that Master of Whispers and Razah have Mysterious armor as their default armor.)
Note: Once you upgrade a hero's armor, you can switch back and forth without losing anything, but you don't recover the Mysterious Armor Pieces.