The Siege of Orgrimmar: Immerseus

Lorewalker Cho’s shock was clearly evident. “What has become of the Vale? The land is scarred! The ever blooming trees and plants wither and die, as the water from the pools drains away.”
“Damn that orc,” Zetsuen cursed as he stared out at the vale, now twisted and corrupted with dark sha energy, from the Shrine of Two Moons. Down below, Sunwalker Dezco and a team of his tauren braves kept the sha manifestations at bay. The normally placid pandaren monk paced restlessly on the terrace of the shrine.
At the railing, Kraft stared out over the vale and narrowed his undead eyes. “This will have consequences. The waters from the vale supply the farmlands in the Valley of the Four Winds. This corrupted water will destroy the crops in the valley.”
Beside him, Jizal shook his head. “Is there a way to purify the sha corruption from the waters?”
Kraft shrugged.
“There is a way.” All three looked towards the doorway of the shrine. Lorewalker Cho was the one who had spoken. “But it is perilous and we will need the strength of many.”
Mal rose from her seat at the terrace. “Worry not, Lorewalker. We have that strength.”
* * *
Lorewalker Cho appeared energized as they journeyed deep below the vale, the rotund pandaren having termed the place the Vale of Eternal Sorrows. “Ah, we adventure together again, except this time I am afraid that the circumstances are much more dire.” The company walked with a renewed sense of purpose, the darkness seeming insubstantial before their determination.
“Once, the Titans used these life-giving waters to create and shape all life in Pandaria,” the Lorewalker explained. “It is these waters that kept the Vale in bloom. Their runoff into the Valley of the Four Winds created the most fertile farmland in the world!”
“And now, the malignance of the Old God has manifested itself within these waters.”
Before them was a massive water elemental, streaked with the dark sha corruption so evident in the land above. Lorewalker Cho was aghast. “Such a foul, foul thing – destroy it, before it seeps deep into the soil and corrupts all of Pandaria!”
Mal hefted her shield in her left hand, her right swinging an axe worn with repeated use. Beside her, Avierra, the blood elf paladin, did the same with her own shield and sword. Side by side, orc and blood elf, the two nodded. Mal performed a heroic leap right at the elemental, axe landing in a crushing blow that made the elemental shudder and ripple, but appear otherwise unharmed. Sha-infused water began to scatter across the hall, burning any who got hit.
“Spread out!” Avierra roared even as she hurled her shield at the elemental in a Light-enhanced throw. “For the Light!”
Bladewisp unlimbered his bow and quickly shot a series of explosive arrows into the elemental even as he moved to the left to avoid the burning patches of sha-infused water. Nonchalance, eyes blazing with raw arcane power, hurled a swirling ball of ice at the elemental, following it with a series of arcane missiles, smashing into the elemental’s frozen torso.
Cyanmyer channeled balls of fel fire to smash into the elemental from its flank, covering the advance of both Jizal and Kraft into melee range whereupon the paladin and rogue wielded the Light and exotic poisons to deal massive damage to the foul creature.
All the while, Zetsuen, Veexie, and Mindmeltt blanketed the company in healing energy, neutralizing the harmful effects of the sha-touched waters.
“Take it down!” Zetsuen roared, seeing the elemental start to weaken and retreat down into the pool of water at its base. The company doubled their efforts and was gratified to see the elemental surge down into the pool, disappearing from view. In the blink of an eye, all was silent.

“Is it over? That seemed a bit… too easy…” Bladewisp whispered.

The pool suddenly swirled, releasing little balls of dark and light colored water. The dark water was infused with sha while the light water appeared to belong to the elemental.

At that point, Lorewalker Cho came to their rescue. “The sha-infused water must be destroyed. It is corrupting the water elemental of the Vale. The light colored water is the elemental itself. See if you can heal the light colored water with your healing spells.”

The water globules landed on the ground and began to ooze back to the center pool. Bladewisp shot multiple arrows into several of the dark sha-infused water oozes, which popped without much effort. The healers, meanwhile, concentrated their efforts on casting healing spells at the light colored water, seeing them glow with health and purity before slipping into the central pool.

The central pool shuddered and splashed, dealing burning damage to them all, but less so than before. It appeared their efforts were paying off! The elemental rose once more, but it seemed smaller than before, weaker for certain. This cycle repeated twice more before the elemental finally shuddered and expelled all the remaining sha corruption from itself.

“Ah, you have done it. The water are pure once more,” Lorewalker Cho said with a satisfied grin. “Can you feel their life-giving energies flow through you? It will take much time for the Vale to heal, but you have given us hope!”

Interlude

"How is Master Taran Zhu?" Bladewisp asked, concern clear on his face.

Kraft shrugged. "I barely got him out of there in time. Veexie and Zetsuen healed all they could just beside the explosion but we had to evacuate the Master of the Shado Pan to Binan Village for further healing." The rogue had risked his life to swoop in at the very last second, carrying the gravely injured Master of the Shado Pan to relative safety.

Jizal slammed his fist into a nearby wall. "That madman Garrosh has much to answer for."

Mal shook her head. "That orc has gone too far. He will pay for his crimes."

Bladewisp pulled an arrow from his quiver. "My advance condolences to our Warchief then. Our path leads to Orgrimmar and Garrosh Hellscream's front door."