Some say that changelings are demons, and some say they are fae. What is the truth lies somewhere in the middle. They are dark fae, the Aos Si, the Unseelie. It is said that they are often switched with human babes, and this is true. The fae-child needs human mother's milk to live. But sometimes, just sometimes, the Sidhe leave the child with the humans, and that child lives a human life.
This is what happened to Marek, though that is his human name. His truename is Athrezoth, and he was raised, for the first few months of his life, by a human couple. However, once they discovered his true nature they were stricken with grief, knowing that their true son had been taken. They thought of killing the babe, but knew that would bring the wrath of the fae down upon them. So they did the one thing they could only think to do; they gave the babe to a nearby monastery.
The monks there were merciful and kind, and though the child was not human they raised him as if he were. They never tried to hide his true heritage from him, and they taught him their ways. As a changeling, a fae, he had deep ties to Nature, and his skills proved to be extraordinary. However, for Marek, he felt something that most fae never feel; guilt. He knew that he truly had no brother, and yet his human parents (for he still loved them) had lost a child through no fault of their own. His time in the monastery had given him human feelings and yet he found he could switch them on and off as he so desired.
As he grew, which was faster than any human, he became more than proficient in the fighting arts and with a multitude of monk weapons, excelling in both the spear and the sword. He loathed wearing armor, though he could wear steel, but like most of his kin, iron hurt him terribly. Leather and other types of armor were fine as well, but he found he preferred to stay unarmored, as it hindered his movement, and his own natural defenses were quite formidable.
Unfortunately, the Monastery of the Veil, as it was known, had many enemies. The Elders knew this, and knew that there was an attack coming. They had sent Marek, along with a few other apprentices, to the nearby city of Caliphas for various supplies. While they were gone the monastery was attacked and razed, the monks slaughtered by their ages old enemy, the First.
The First is a cabal of killers, and they hold themselves to no standards. For the right price, they will kill anyone; men, women, even children. The monks opposed them, their own martial prowess legendary, and anointing themselves protectors of the innocent.
When Marek and his brothers returned to the monastery they were shocked. Of course the monks had kept Marek's true identity from his brothers, but in his rage and despair his form slipped and they saw him for what he was for the first time. Unsure of what to do the small group of apprentices renewed their vows of brotherhood to one another and set out on their own, to not from The First and to also teach their skills to others. Eventually they knew they would have to face The First and they needed to be prepared.
For Marek he still wanted to get his human family's brother back as well. So now he is a wandering monk, helping those he can and keeping his identity a secret, as he travels in a human form. He has two forms he takes, that of a wandering traveling monk, and that of a powerful mystical monk. Both forms, and all his human forms, are completely hairless, as is his true form. He has found he cannot replicate hair, and so all forms he takes are completely hairless.
Over time he has grown in power, and in a need to feel some sort of camaraderie as he's been separated from his human family, and then his monk brothers, he joined the Adventurer's Guild. Over the years he has risen through the ranks, though he is particular about what sorts of deeds he does. People look upon his kind with suspicion, and only the Guildmasters know of his true form.
He is deadly unarmed and quite efficient in his movements. He is an excellent swordsman and also lethal with the spear. There is not a monk weapon he is unskilled in. He has deep ties to Nature and uses Spirit Magic, which allows him to heal himself and others, and to call upon the energies of all living things around him for offense and defense both.
Marek's True Form.
Marek focusing his Spirit.
Marek as the Wandering Monk.
Marek as the Mystical Monk.