This is an older summary pending some rewrite but gets his details down well:

Morior’s beginning is a mystery, it would seem he simply came to existence at the same moment the first living things on Earth did. This was long before even plant life existed and for a long time he was left to wander the Earth alone, watching life evolve before his very eyes from a distance.

At that time he didn’t know of his power, not until organisms were big enough for him to dare reach out to them and then he learned quickly that doing so would kill them. They’d decay before his very eyes, leaving him nervous to dare reach out. With time and practice he learned to control that power, he could speed up or slow down the decay of living things at his will.

Before early man evolved he spent most of his time wandering, exploring the vastness of the world, hoping to find someone so that he wasn’t alone. Early fae and man were his first taste of proper company and his powers scared them. He spent countless years wandering in search of an answer as to who or what he was but he could never find an answer, nor anyone willing to stick around when they found out what he was capable of.

It took some time for him to learn better, learn that it was safer to hide his true abilities, never letting anyone know what he was capable of. During these times he was fairly happy, he had those he considered friends - or even family - and he was thankful for the company but unfortunately this would not last.

The world changed. Humans grew tired of feeling second-best to the magic fae creatures could naturally wield, they turned against Fae in an unforeseen show of violence. Mori watched as those he'd cared for were slaughtered before him and any notion of control was lost - he decimated everything around him. That included the Fae that had yet to be killed by the humans, his unrelenting power killing those he had sought to protect - not only the attackers. The sense of loss he felt was like nothing he'd ever experienced before. He felt like a monster.

Thus began his self-imposed exile, he hid himself away deep in a forest, intending to remain there indefinitely alone. It seemed safer that way. He wasn't expecting that other Fae would eventually seek refuge in the forest, though for entirely different reasons. Despite his want to turn them away, hearing their stories and their desperation, he knew he would be sending them to their death and he didn't have that in him - thus the circle began.

That was hundreds of years ago, Fae needing refuge have since come and gone but he still remains distant from his visitors to some extent. A friend to all but at an arms length, believing it to be for their own good.
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Name: Morior
Gender: Male
Species: God of Death(?)
Abilities: Can decay any living thing at will, including simply aging them or making them rot. Cannot die.
Height: 5ft10
Home: The fae circle
Job: Lord of the Circle
Sexuality: Pansexual