Eventually transfigured into a winged Satyr.
Of average kaldorei height and appearance, Eraelan Netherbane never would have stood out within a crowd. However, his years of hunting the fel have changed his look, darkening his skin and hair to a deep purple from the original lighter shade of blue it once was.
Eraelan's hair is long and largely unkempt. He chooses to let most of it fall free, but he does tie back a small bit of it in a topknot. He keeps his face clear of hair, but his cheeks and chin he lets grow.
Finally, Eraelan, like all of the caste, wears a blindfold around where his spectral sight now replaces his once silvery eyes.
Eraelan's demonform looks much like any other satyr with one major exception: wings. His bestial fur is crimson in color, and his skin has grown even darker yet. In addition to this, Eraelan's experiments in flesh shaping has allowed him to gift himself with a pair of massive feathery wings.
It is unknown whether this means he was capable of flight. And since Eraelan Netherbane is now dead, we will never truly know.
Before the first invasion of the Burning Legion, Eraelan Nightbane was one of the kaldorei Moonguard. He stood alongside his two brothers, the older and more skilled Eraelus, and the younger and less refined Eraelor. The three were sorcerers of little renown, but their abilities were put to the test when the Burning Legion came.
The three brothers could count themselves lucky to have been a part of the host of night elves that fought the main thrust of the demon invasion. They fought alongside other moonguard, including the newly promoted Illidan Stormrage, whose brash approach to sorcery nearly killed as many allies as it did enemies. It was Illidan's recklessness that soured the image of the one who would be known as The Betrayer.
One night, during the very brief amounts of rest that the soldiers and sorceres were allowed at the rear lines, a vision came to the three brothers at the same time. A voice spoke in their dreams, calling them each by name and offering them power... power that could rival even the careless sorcerer who had been decimating the Legion's ranks. Upon awakening, the brothers spoke nothing of this vision, each fearing it for what it was--a temptation dangled in front of them by the Burning Legion.
However, a day or so later, when the brothers were able to catch their hour or two of rest, Eraelan noticed that Eraelus had gone missing. Not wanting to wake the younger of the three, Eraelan set off into the woods to find their wayward third. He succeeded.
Deep within a forest that now perhaps lies at the bottom of the sea, Eraelan found Eraelus standing before a large searing red being that called itself " Sraath." He would later known these demons as "doomguard." The massive beast spoke to Eraelus and offered him the same power that the dreams and visions had mentioned. To Eraelan's shock, Eraelus did not deny the power. He did, however, falter when he learned that the price for the gift was the betrayal of the host. Eraelus, always the most adept at wordcraft between the three, told the demon that he would give a final answer on the next day.
Eraelan returned to the camp to find Eraelor awakened and worried for his older brothers. Quickly, Eraelan explained what he saw, but urged Eraelor to make no mention of it. Eraelan had a plan forming in his mind, and it required Eraelus to expect no change from his younger siblings.
The next day arrived, and the three brothers were once against shuffled off the front lines and allowed to heal and rest. Eraelan watched in anticipation as Eraelus strode off into the forest when he thought the other two were asleep. Immediately both Eraelan and Eraelor stalked after him. It was not long before they reached the same spot. But this time, instead of one doomguard there were four. Two rather large ones, one being this Sraath, the other an unknown. Flanking them were two smaller doomguard.
As Eraelus stepped into the clearing, clearly shaken by the new additions, Sraath turned and sent forth his two lesser guards to attack Eraelan and Eraelor, who had been seen by the agents of the Legion. Shocked that his brothers had followed him, Eraelus stood stunned as the two brothers fought against the marauding demons. But he was able to recover quickly, and regardless of his previous choice, Eraelus struck back against the doomguard.
The battle was intense but short. Somehow, the three brothers had survived, and the two doomguards lay dead upon the soil. Sraath and the other, larger doomguard, however, stood with amused grins upon their twisted faces. With no words, they turned and flew off into the distance, back to the Legion's masses.
That event changed the brothers eternally, even after the Burning Legion had been swept from Azeroth. Eraelus turned more inward and began to seek ever increasing power from his arcane studies. Eraelor, seeing the damage that magic could wreak, stopped practicing sorcery and began to look into learning druidism. He, along with many others, had heard of the things that Malfurion Stormrage, brother to the maligned Illidan, was able to do with nature's blessing.
Eraelan, however, was the most changed. After the sundering, after the landmass had split itself, he began to wander what was left of the Legion-scarred lands. It is unknown was transpired during this "walkabout," as Eraelan was never known to have imparted the tale. What is known, however, is that when Eraelan returned to the re-founded cities many years later, he wore a tattered blindfold over his eyes, which now glowed with a strange energy. He also carried two savage looking blades and wielded them with a skill that a pure sorcerer would have never managed.
Eraelan learned, upon his return, that Eraelus had gone with the Quel'dorei exiles, never to be seen by either brother again. He had also learned that Eraelor strictly disapproved of Eraelan's "glorifying" of Illidan's path. Having lost one brother to exile and seeing that his only remaining one would be little more than a hindrance, Eraelor stepped deeply into the dark forests of Ashenvale. He no longer chose to go by his family's name of "Nightbane," but instead chose a more fitting name of the path that he sought to follow. He chose to become Eraelan Netherbane, demon hunter.
It was some time later that Eraelan set up a small camp where he would begin his teachings. He was able to gather together a few students and teach them the ways of the path, keeping careful watch on their progress and measuring their abilities and skill.
He thus discovered that his created rituals gave his students similar abilities to him, but they also came with dire side effects. Madness was the most common and most devastating, as most of the hunters bound to demon souls could not cope with the extra taint upon their minds and spirits. Only a few could withstand such a thing, and these became Eraelan's more prized pupils.
Unfortunately, his most skilled, a young huntress named Elaia Shaillan, was not immune to the madness, and she caused the most devastation amongst the camp. Eraelan was forced to send perhaps his most stable hunter, a student by the name of Tharion, to kill her. Tharion was successful.
Tharion's stability was largely due to his outlook on life, which was very "grey." He had a habit of seeing situations from both sides, and few things to him were truly good or evil. Tharion was a rare creature who saw the world for what it was, not for what he wanted it to be. As such, Eraelan bestowed the name "Greyseer" upon him, and he has since been known as "Tharion Greyseer."
Even after the death of Elaia, Tharion stayed under Eraelan and learned. He proved himself to be quite skilled at hunting mad hunters, and Eraelan used him to that extent many many times. It was not until the Third War came upon Kalimdor that Tharion and his mentor parted ways.
Sometime during that war, Eraelan vanished, and when Tharion returned to the camp, all he found was a barren, broken site. Saddened by the fact that he would never truly be able to complete his training under Eraelan, Tharion set out to wander the world and see about completing it alone.
It was not until much later, when Tharion was finally succumbing to the madness of Eraelan's altered binding, that the hunter discovered the true fate of his old mentor. Tharion discovered Eraelan somewhere within the Twisting Nether, deep within an old ruin of some sort. His body was transfigured, turned into that of a satyr by the Burning Legion. But even as a demon Eraelan could not give up his experimental ways, and had developed another ritual which he used to transfer the soul of Tharion's demon into a specially forged blade that would eventually be known as Felborne.
That was not the only experiments that Eraelan had done, however. He had practiced as the demons had done, twisting life from its natural state and into a more demonic form. He had even practiced upon himself, gifting his twisted satyr body with that of two massive feathery wings. Seeming to enjoy his new found abilities and demonic existence, Eraelan even took up a satyr-like name, the full length of which is difficult for mortal tongues.
Eraelan continued to keep contact with Tharion after the rebinding of Felborne, although it was a sporadic and unreliable contact. Eraelan was the first to warn Tharion that the Burning Legion had turned the Shadowed Sun upon them, and that a pit lord by the name of Daeloth was on the loose and hunting.
There were many times when Eraelan appeared to be an ally, giving warnings and assistance to keep Tharion alive. However, it was soon discovered by Xythael that Eraelan's motives were not fully selfless. It was then that she began to plot ways of removing Tharion's old mentor from the picture altogether.
After Daeloth was defeated, Tharion and Xythael found themselves at odds with a different type of hunter, the Shai'i (a twisted version of Elaia, the hunter that Tharion had killed long ago). Daeloth had convinced them that he could assist (since he was being hunted as well), but would need to regain some of his former strength to do so.
When Xythael asked what he needed, Daeloth responded that feeding upon his own kind was one way of regenerating that which had been lost. Xythael, finally seeing her chance, lured both Daeloth and Eraelan into a confrontation.
And while it was Xythael who fought and defeated Eraelan, it was Daeloth who fed upon the fallen former hunter, regenerating the arm lost in the battle with Tharion and regaining a measure of strength.
Daeloth keeps the skull of Eraelan Netherbane as a trophy. You can still see it today upon the tip of the mace he carries with him into battle.
As a side note, the name of the guild, "Netherbane" was chosen before Tharion discovered Eraelan's true intent. He had chosen it to honor the memory of his lost mentor, not knowing that Eraelan was perhaps the farthest thing that needed to be honored.
Tharion chooses to keep the name, however, as a reminder of what NOT to become.