Expansion 4 - level 85-90
This is the Emerald Dream Expansion; Nightmare's Grasp
ILLIDAN AND THE DEMON HUNTERS:
When Illidan absorbed the Skull of Gul'dan, he gained not only the memories of the Warlock but his spirit as well. Gul'dan whipsered to Illidan, convincing him to do dark acts he would not have otherwise. When Arthas struck down Illidan at the foot of the Frozen Throne, Gul'dan seized control from Illidan. After Illidan's body, under Gul'dan's control, was slain by Maeiv in the Black Temple, his spirit escaped to the Emerald Dream, where he became trapped in the Emerald Nightmare. However, Gul'dan also escaped to the Emerald Nightmare.
In the Nightmare corrupted area know of the Ravine of Shadows Illidan learned to control the powers of the Nightmare and the power of Vengeance. In time, Illidan founded a new order of Demon Hunters.
THE EMERALD NIGHTMARE:
After the powers of the World Tree were depleted to defeat Archimonde, an Old God was able to corrupt the Emerald Dream, creating the Emerald Nightmare, a bastardized version of the Dream. The Nightmare was initially led by the Old God using Eranikus as a puppet. However, when he was purified, he revealed himself fully and took personal control.
However, he was not alone. Archimonde's spirit had been sucked into the Emerald Dream. When the Old God tried to assault the Eye of Ysera, Archimonde performed a sneak attack and took control of the Nightmare. The Civil War of the Nightmare followed, from which Archimonde, supported by Gul'dan, emerged victorious, and the Old God retreated into the Mountains of Madness.
The Civil War allowed the forces of the Emerald Dream to establish foothold in the Nightmare to strike back. Archimonde now summons demons to help him engulf the entire Dream in the Nightmare. He leads the Nightmare, with Gul'dan, Mephistroth, Gorgonnash and Prophetess Xelinnas, a shivarra, as his four lieutenants. However, given Gul'dan's past, his loyalty is doubtful; indeed, unknown to Archimonde, he in fact serves the very Old God he helped overthrow. Archimonde rules the Nightmare from the Burning Canopy in the Dark Tree Sardrassil, an evil and perverted version of the World Tree Nordrassil.
- The Prophet's Cave (58-62) Adjacent Zones: Stonetalon Mountains (via entrance)
- The Groves of Cenarius (83-86) Adjacent Zones: The Hinterlands [Seradane], Ashenvale [Bough Shadow], Feralas [Dream Bough], Duskwood [Twilight Grove], Crystalsong Forest [Great Tree] (via portal), The Eye of Ysera, Stormrage Hills, the (via foot)
- Twisted Paradise (83-86) Adjacent Zones: The Eye of Ysera (via foot)
- Stormrage Hills (85-87) Adjacent Zones: The Groves of Cenarius, The Emerald Inferno (via foot)
- The Mountains of Madness (85-87) Adjacent Zones: The Twisted Paradise, The Emerald Inferno (via foot)
- The Emerald Inferno (86-88) Adjacent Zones: Stormrage Hills, Mountains of Madness (via foot), the Dark Tree/Sardrassil (via flight)
- The Dark Tree (88-90) Adjacent Zones: The Emerald Inferno (via flight)
- The Eye of Ysera (Sanctuary) Adjacent Zones: Ravine of Shadows, The Twisted Paradise, The Groves of Cenarius(via foot)
- The Ravine of Shadows (65-68) Adjacent Zones: The Eye of Ysera (by foot)
The Prophet's Cave: Located high in the Stonetalon Mountains, it was here Medivh lived during the Third War. Though he has left, the mysterious aura of tha place has not. The halls still possess great power, and the deeper tunnels have been invaded by forces of the Nightmare seeking to claim these powers for their master. Also, a strange mage has taken up residence in a room of the Cave, offering Visions of self discovery to all that greet him.
The Groves of Cenarius: Ancient forests inhabited by Cenarius himself, these are the least corrupted parts of the Nightmare outside the Eye of Ysera. However, the Nightmare has seeped ion through Stormrage Hills, and there is growing demonic corruption in the east in the form of the Demonic Front. Inspiration: Middle Kalimdor, especially Feralas, and Ashenvale
Twisted Paradise: This coastal region was once a lush rainforest and jungle. However, the Nightmare has taken hold, corrupting it to its very roots. Here, Nightmare Trolls seek to build a body for their fallen god Hakkar, whose image commands them. However, this is not Hakkar but a guise taken by Archimonde to enlist the trolls into his forces. Inspiration: Azeroth (continent)
Stormrage Hills: A region of rolling hills named after Malfurion Stormrage himself. The area has unfortunately been subject to the corruption of the Nightmare. However, the Nightmare Civil War allowed the Nightmare to be pushed back. Now, a large, living wall separates it from the Emerald Inferno. Inspiration: Ashenvale
The Mountains of Madness: These Mountains are so corrupted by the Nightmare that they have begun to split of from the Dream, with small rifts appearing around it, but this process is just beginning. Everything that lves here is Nightmare incarnate. It is here where the Nightmare first appeared, as it is the dwelling of the Old God that created it. Inspiration: Khaz Modan
The Emerald Inferno: This area has been affected irreparably by the Nightmare. After being corrupted by the Nightmare, is was corrupted even more by intense fel energies by Archimonde. Fel fire burns beneath it, coming put and engulfing the maddening land in emerald fire. Off the coast to the west, the dreadlord Mephistroth rules over his keep, while in the east Gul'dan has constructed a tower facing the Mountains of Madness. Inspiration: Northern Kalimdor, Lordaeron, Northrend
The Dark Tree/Sardrassil: This enormous tree was once the counterpart to Nordrassil, but when the World Tree lost its energies, so did it. When Archimonde took over the Nightmare, he captured the tree and corrupted it, naming it Sardrassil in honor of Sargeras. It now serves as the main hub of the Nightmare's forces. At its top is the Burning Canopy, from which Archimonde rules. At its bottom are the Blackened Roots, where Archimonde works to enfuse his demons with the powers of the Nightmare, and the Nightmare with the power of demons. Inspiration: Nordrassil, Teldrassil, and Vordrassil
The Ravine of Shadows: These canyons are home the Nightmare's main assault against the Eye of Ysera. Here, the spirits of the Dragons of Nightmare work to overtake the Eye and crush the Emerald Dream once and for all. In the middle area of the Ravine Illidan and his new order of Demon Hunters train, waiting to prove themselves worthy allies to Ysera. Inspiration: The Great Trees, Deadwind Pass
The Eye of Ysera: The home of the Green Dragonflight. Here the Aspect Ysera commands her forces against the Nightmare. However, she has been corrupted by the Nightmare, and is in a coma fighting the evil within her. The few orders she manages to give are not decisions her true self makes, but her Nightmare side. Inspiration: Moonglade, Wyrmrest Temple
- Vision of Truth: The Prophet's Cave (patch 5.2) 
- The Demonic Front: the Grove of Cenarius 
- Zul'Hakkar: Twisted Paradise (patch 5.1) 
- Barrows of the Mad: Stormrage Hills 
- The Lair of Nightmares: The Mountains of Madness (patch 5.3) 
- Mephistroth's Keep: The Emerald Inferno 
- Burning Canopy: The Dark Tree/Sardrassil (patch 5.4) 
- Shadowflame Ascent: Ravine of Shadows 
- Vision of Thoughts: The Prophet's Cave (90)
- The Deep Tunnels: The Prophet's Cave (90)
- Mannoroc Echoes: The Groves of Cenarius (84-86)
- Isle of Regret: The Groves of Cenarius (86-87)
- Bay of Blood: Twisted Paradise (84-86)
- The Warped Grotto: Stormrage Hills (85-87)
- The Halls of Corruption: The Mountains of Madness (86-88)
- The Shattered Way: The Mountains of Madness (90) (patch 5.3)
- The Blackened Roots: The Dark Tree/Sardrassil (90) (patch 5.4)
- Gul'dan's Tower: The Emerald Inferno (87-89)
- Eye of Eranikus: Ravine of Shadows (89-90)
- Heroic Wailing Caverns: Northern Barrens (90)
- Heroic Blackfathom Deeps: Ashenvale (90)
Saving Ysera: Save Ysera from the dark corruption of the Nightmare. Major Characters: Malfurion Stormrage, Illidan Stormrage, Cenarius, Fandral Staghelm, Ysera. Areas: Every zone of the Emerald Dream
Fall of Staghelm: Witness Fandral Staghelm's fall from grace. Major Characters: Fandral Staghelm, Ysera, Illidan Stormrage, Archimonde Areas: Stormrage Hills, The Emerald Inferno, the Eye of Ysera
Stormrage's Redemption: Illidan and his demon hunters redeem themselves. Major Characters: Ysera, Illidan Stormrage, Cenarius, Malfurion Stormrage Areas: The Ravine of Shadows, the Eye of Ysera
Illidan's Vengeance: Illidan seeks to take vengeance upon Gul'dan. Major Characters: Illidan Stormrage, Gul'dan, Malfurion Stormrage Areas: The Emerald Inferno, the Mountains of Madness
- Ysera: The Green Dragon Aspect, she rules over the Emerald Dream. However, the Nightmare has affected her, and she sleeps not only in the Physical World but in the Dream as well.
- Cenarius: The great demigod Cenarius, patron of the druids, helps fight the Nightmare and leads the Emerald Dream while Ysera is disabled by the Nightmare. His body was slain by the orc hero Grom Hellscream, a crime which he has forgiven the orcs for committing; those around, however, have not.
- Malfurion Stormrage: The great arch-druid and second in command to Cenarius, Malfurion leads the Armies of Cenarius against the Nightmare.
- Illidan Stormrage: The half-demon twin brother of Malfurion, Illidan is a mighty demon hunter. After consuming the Skull of Gul'dan, he was possessed but the Skull's original owner, Gul'dan himself. When his body was killed in Outland, his sprit found its way to the Nightmare, where he raised an order of demon hunters and earned the trust of the green Dragonflight and the Armies of Cenarius.
- Fandral Staghelm: The leader of the Alliance forces against the Nightmare, Fandral is a powerful but arrogant leader, utilizing guerilla tactics to fight the Nightmare. He is still haunted by memories of the War of the Shifting Sands, of the death of his son.
- Broll Bearmantle: Second in command of the Alliance forces, Broll disagrees with the tactics used by Fandral, preferring a safer, more calculated approach.
- Bashana Runetotem: Daughter of Hamuul Runetotem, she leads the Horde forces against the Nightmare. She extremely devoted to the ideals and path of the druid. She often clashes with more moderate druids.
- Hamuul Runetotem: Second in command of the Horde forces, he would have lead the Horde offensive but he thought himself too old. He advises his daughter, and hopes to ease some of her fervor, for fear that it could cause a schism in the Horde.
- Archimonde: Lord of the Burning Legion and now master of the Nightmare, Archimonde seeks to destroy the Dream and send all of Azeroth into an eternal Nightmare. He has been transformed by the energies of the Nightmare
- Gul'dan: This terrible warlock was thought gone, but he in fact possessed Illidan after he absorbed the energies of Gul'dan's own skull. When Illidan's body was slain, he followed Illidan's spirit into the Nightmare. He joined Archimonde in taking over the Nightmare, but his loyalties are of suspect. Unknown to all, he had defected to serve the very Old God he helped defeat, who has given him maddening powerful abilities.
- Mephistroth: Lord of the Nathrezim, Kil'jaeden sent him to the Nightmare to help Archimonde in consuming the Dream. From his Keep off the western shore of the Emerald Inferno he assaults the Stormrage Hills. Like his master, he has been transformed by the Nightmare.
- Gorgonnash: The current leader of the pit lords and the annilhilan, he took over from Azgalor after his failure at Mount Hyjal. He came to the Nightmare at Archimonde's request.
- Prophetess Xelinnas: The leader of the shivarra, she inspires the armies of the Nightmare with her speeches and sermons.
New Hero Class: Demon Hunter
Demon Hunters: Demon Hunters are fusion between WC3 Demon Hunters, Druids of the Nightmare, and Wardens. They are a DPS/Healing Hybrid class.
- Fel (Spell DPS)
- Vengeance (Melee DPS)
- Nightmare (Healing)
Expansion 5 - level 90-95
This is the Maelstrom Expansion; Tides of Doom. More coming soon...-ish