The Crystallized Costumes are a set of themed costumes that are standard garbs in crystal form. Only The Apprentice, The Squire, The Huntress and The Monk have a Crystallized Costume.
All four costumes are were only available to players who have backed $300 (Ultimate Tavern tier onwards) or more on the Dungeon Defenders Awakened Kickstarter during the period of March 6th 2019 'till April 11th 2019.
These costumes are currently no longer available.