Crystalian

Una Crystallum, commonly called Crystalians, are large, humanoid constructs composed entirely of shiny blue / purple crystals. Crystalians can be one of three types: Spear variant, Boomerang variant, and Brute variant. 

Crystal Asteroids. Crystalians are the protectors of the Crystal Asteroids. These asteroids are covered in crystals of varying rarities, values, and sizes. Most of these crystals are unbreakable by conventional means, requiring special magic and tools to break. These asteroids can range in diameter from 150 feet to upwards of 900 feet. The most valuable part of these massive asteroids is the small gem inside; The Purple Heart.

The Purple Heart. The Purple Heart is a tiny purple crystal in the middle of the Crystal Asteroids. It is located floating underneath the massive white crystal that powers the asteroid. Its uses can vary depending on the great mind behind the usage of it, but generally they are used to empower rituals, as they contain a strong affinity towards magic. These Purple Hearts cannot be moved from their location unless the Crystalian(s) protecting it have been destroyed. 

Loyal Hearted. The origin of the Crystalians is unknown, all that is known is they have no organs, no emotions, no personality. They are constructed and live only to defend the Crystal Asteroid and its Purple Heart, and will continue this objective until their destruction.

Crystalians forever stay inside of Crystal Asteroids, protecting The Purple Heart within each one. The exterior of the asteroids are covered in crystals of varying rarities, values, and sizes. The inside has a massive white crystal that powers the asteroid, and the tiny purple crystal called The Purple Heart floating underneath it. When a creature enters the Crystal Asteroid, the massive white crystal emits a blinding white light. Each creature that can see the crystal must make a DC 15 Constitution saving throw or be blinded for 1 minute. A creature can repeat the saving throw at the end of each of its turns. 

Lair Actions

On initiative count 20 (losing initiative ties), the Crystalian takes a lair action to cause one of the following effects; the Crystalian can’t use the same effect two rounds in a row:

• The Crystalian chooses a 10 foot area of crystals on the walls of the interior of the asteroid, causing them to shoot out towards a target of the Crystalian's choice. The target must make a DC 15 Dexterity saving throw or take 10 piercing damage. 
• The Crystalian focuses on the magical energy of The Purple Heart, causing it to shoot out a purple beam towards a target of the Crystalian's choice. The target must make a DC 15 Constitution saving throw or be stunned until the next lair action.