Matryoshka Shell

Matryoshka Shell is a legendary level 55 chestplate, given as a reward upon killing the Matryoshka Idol. It gives several miscellaneous bonuses, Walk Speed, XP Bonus and Loot Bonus. It's main advantage is its massive elemental defenses, and massive XP bonus you can use to level quickly.

Obtain
The Matryoshka Shell is dropped by the Matryoshka Idol located at:

Note that this is only the access point and not the actual boss room.

Lore
"The armor worn by the enigmatic Matryoshka Idol. It appears to have a nearly uncountably high number of inlets and sockets set inside."