After escaping Limbo, Stygian had begun to rapidly age. As an ordinary pony with weak unicorn magic he was perceptible to the drastic change from Limbo's stagnant time space to current day Equestia.

In only to stop this from turning him into dust, he accepted a bit of the Shadow's magic once again. It took him many months, with the help of Star Swirl, Twilight and Sunburst to control the Shadow's magic from taking over again.

But a problem Stygian faces is immortality, because of the Shadow's magic keeps him from aging.
he is able to control his growth, at this moment he is in a 30 year old body. But something the Shadow Essence is unable to control is his hair, which will grow in rapid rates then fall off before it regrows all over again.

Stygian is a awkward and somber adult who still has a mind of a teenager. He can be easily pleased by giving him food and currently lives and is monitored by Sunburst for his studies.

Other Headcanons:

• Stygian is Asexual Biromantic!
• Stygian has ADHD
• Stygian did not originally have a cutie mark; he was a blank flank up until current day where he gained his cutie mark from harnessing Umbra.
• Stygian’s father, Shadow Hoof was a leader of a quiet underground cult founded in Hollow Shades.


MAJOR CANON DIVERSIONS:
Can be found in my Star Swirl’s Post HERE

tldr: The Pillars of Equestria did not plant a seed that ultimately turned into the Element of Harmony. They did trap Stygian in limbo tho.


Lore Headcanons:
Shadow Essence// Umbra Magic:
Umbra is the state of emptiness and darkness that inhabits every magical creature. Some are able to control it, like the Kirin and others are completely consumed by it, like Sombra.

• Sombra had found a artifact made out of pure Umbra which destroyed his physical body leaving him as a shadowy spirit.
• Kirin are a special case of creature that needs to control their unsteady amount of Umbra or else they become a Nirik.
• Magical creatures like the Bugbear are the product of a phenomenon involving Umbra. A process that happens naturally in the wild were two or more animals fuse together. This doesn't happen as often now.
• Nightmare Moon and Daybreaker are the products of being consumed by the Umbra of either sun and moon.


Cult in Hollow Shades:

A cult was built under the noses of the residents of Hollow Shades. It was obsessed with collecting Umbra from unicorns and other magical creatures and refining them into artifacts. The cult believed that Umbra could be collected and destroyed to rid evil from all of Equestria. A noble choice. But the way they went about it, misunderstanding the natural laws of magic in Equestria they failed to understand that Umbra and normal Magic were intertwined; it was how you went about controlling it was what defines Umbra, they ultimately hurt more people than helped.

Stygian was groomed to become the next leader of this cult up until he met Star Swirl, his idol and more of a father figure than Shadow Hoof. It was only after he felt betrayed by the Pillars of Equestria did he run back to his father. Who welcomed him open arms. Stygian selfishly used one of the artifacts and was consumed by Umbra. He destroyed his village and after his subsequent defeat and banishment to Limbo, the cult disbanded and faded over time. The remaining artifacts were either destroyed or stolen.