Merlin

It is said that even nature itself would have risen up to defend Merlin, and this is not far from the truth. Merlin was born in the Middle Ages and attended Hogwarts. Being sorted into Slytherin, he was taught by Salazar Slytherin himself.
Merlin always had an affinity for nature. Even as a young boy he felt each blade of grass, each leaf on the tree, had a personality and a story he wished dearly to discover.
So naturally, his time at Hogwarts was dominated with exploring the Forbidden Forest. His trips became so frequent and his determination to explore so fierce his fellow students took to calling him ‘the Wild Man of the Woods’. However, their jeers would not dissuade him as his paths probed farther and farther into its depths.
Eventually, he caught the attention of the protector of the Forest, an ancient spirit named Bramble. Annoyed by the young boy’s intrusion, Bramble was preparing to teach him a lesson about disturbing ancient spirits when she felt something familiar in the boy. The way he interacted with the nature surrounding him; the way he leapt from root to root, examining every meadow, inspecting every crevice, with a deep and sincere reverence for the life held inside. It was as if this boy’s aura held within it the patient sagacity of an animal- exploring, discovering, but always in harmony with the nature it sees.
As much to Merlin’s surprise as her own, she introduced herself to him, and with this introduction an alliance formed that would never be broken. Merlin continued to explore the untrod paths only Bramble traveled, and the Forest taught him Nature’s magic- wandless, slower, yet far more powerful than those energies typically wielded by wizards. He learned to awaken nature at his need, a skill which saved his life on several occasions; for a friend of nature is never truly alone.
After his graduation Merlin decided to explore England, helping Muggles in a way only a wizard can, so Bramble fashioned him a wand made from the wood of her first child, and powered by a core forged from a lock her hair, so that he would never feel far from her. 
Merlin returned to the Forest often, regaling Bramble with the stories of his adventures; and even though years passed Bramble always saw Merlin as the same, for being ageless she had no understanding of growing old. Their bond flourished and each shared their darkest secrets, with Bramble even revealing her greatest treasure, the Forest vault buried deep within her realm. So close had they become that the Forest would whisper in excited anticipation whenever Merlin’s aura grew near.
Years turned to decades, but although time takes no toll on the eternal, it’s relentless flow dearly taxes mortal men, and unknown to Bramble, Merlin had come to sleep on the roots of her trees one last time. He had come to die.
There are many legends surrounding the passing of the world’s greatest wizard. Some say he was tricked by a sorceress, while the most ancient texts claim he died in the arms of the Lady of the Lake. But these tales only hint at the true sight during Merlin’s death- the forest wept.
A lamentation never seen before or since permeated the Forest; as if each blade and branch sobbed with a cry just almost heard on the slow sad breeze. Those in witness say a mist as thick as a lake’s fog filled the forest until the tops of the tallest trees appeared like islands jutting out of a mournful sea; and every leaf dripped with Bramble’s tears.
Many believe the cries of the living can be heard by the dead; but as Bramble wept, nature herself grieved and that torment echoed throughout eternity. Merlin heard her pain. Grief stricken at the despair of his friend, he cast one final spell- a gift to one he held so dear. Dissipating his energy throughout her realm, he awakened nature one last time, strengthening her realm substantially, and ensuring that Bramble, the Ancient Spirit of the Forest, and his friend, would never feel far from him again.
It is said that even Merlin himself would rise up to defend the Forbidden Forest, and this is not far from the truth.