Vampires

"Where once there was man, with a little darkness, eclipsed by the God-given light of his own soul; there was now a beast, made inside out of darkness, empty of light, save for what it takes from the unturned."
- Corelli Shireshelli , A Word on Metamorphoses
When The Dark Star  descended upon the land that would come to be known as Shatterstar  and became the subject of intense study by Elvari  scientists, the elves that lived in that land would be transformed by the Dark Star's Magick into the species known today as the Noctari. When even this did not sway all of the scientists away from their abuses of the rock, they began to transform even further. These Noctari who would pry deeper into the energies of The Void  would become all-consumed by the phenomenon now known as Void Hunger  until they were twisted into eternally emaciated grey beasts. Furthermore, as they had become so deeply brined in the powerful Death Magick that pulsed within The Dark Star, the only way for a Vampire to survive is to consume the heart of a still living Xelestarian and devour their Nascent Light directly. 
Prolonged exposure to the necromantically charged comet has left any afflicted by this curse entirely incapable of being exposed to direct sunlight lest the affected area be left with permanent bubbled scars. Some believe this weakness to be the direct work of Primos  as He is believed to severely pity the monsters that Elven curiosity has wrought, believing death by divine fire to be an overly generous yet necessary fate for any of these creatures.
Vampirism preys on the biological addiction to magick present in all elves, heightening this need to the point that it permanently damages the brain and leaves them in a permanent animalistic state.
Half-elves of non-Noctari descent are especially resistant to the Vampiric Curse, as they have an innate affinity for blood magick and can simply purge the toxins from themself in most cases. Half-elf children with a Noctari parent however are especially likely to succumb to the disease after a Vampiric attack, due to the already high concentration of Black Magick in their system.