The cure.

They thought and plotted, unable to come up with an effective way to get him out. Months passed. When Eroth wasn’t plotting with Prin, or being subjected to innumerable tests by the order, he was spending his time taking out his frustration and restlessness on Marri, by way of fucking her like mad. It surprised him that despite knowing she was his wife, and his deep love for her, that he quite enjoyed getting Reign in on the games.
Eroth had introduced Marri and Reign to Cammi. He confided in Cammi of their past and of his love for her. Cammi was hesitant at first, but in the months that past, she warmed up to Marri.
Marri wondered if she’d ever have her Eroth back. If not, would she ever get this Eroth free so they could truly be together? If not, would she be able to handle staying in Stormwind for the rest of their lives?
Reign was going absolutely stir crazy. Windhorn however had spent a good portion of his life in captivity. It didn’t honestly bother him much.
But as time passed, Eroth appeared to be growing ill. He tried hard to fight it and even harder to hide it. Especially from the order and from his sister.
Marri’s worry grew each day. After a time, he was too ill to hide it. One day, he simply lay in bed, not getting up. Marri tended him lovingly, helping him eat and drink.
Reign watched from the doorway. “I know this illness.” He said, frowning.
“What is it?” Marri asked.
“The plague.” He said. “The order brought him back to life, but they didn’t cure the plague.”
“What do you mean? He was killed by a dragon.” Marri said.
“You don’t become undead if you don’t have the plague. You don’t have to die of the plague to become undead. You simply must have it.” Reign said. “We won’t catch it... but he’s a danger to every human here. It could become an epidemic. Stormwind could become the latest in the cities that have fallen to the scourge.”
“I t’ought de fall of Stormwind be a good t’ing?” Marri asked.
“Falling at the hands of the Horde would be a victory. Falling to the Scourge would be a disaster. It would only increase the Litch king’s hold.” Reign said.
“What do we do?” Marri asked.
“We have to get him out of here and to Lady Sylvanas.” Reign said. “For all of our sake.”
“We’ve been trying.” Marri said.
They heard the door open. The both turned. In walked the head of the order. Reign blocked his way.
“Get out of my way, slave.” He ordered.
“Eroth is ill.” Reign said. “He’s contagious. You must leave.”
“I will not. Get out of my way.”
“No! You must leave. He has the plague. You’re experiment failed! All you’ve done was condemn him to another death and the chance of becoming a mindless slave of the Litch King!” Reign growled. “And chance spreading the plague to everyone human here! You may have doomed the entire city!”
The head of the order stared at him with wide eyes. He shoved the Blood elf out of the way to see for himself. He pulled a silk handkerchief and covered his mouth and nose. “By the light.” He said.
“You see. We need to get him out of here.” Reign demanded. Marri ignored the head of the order, continuing to tend Eroth who had become delirious with fever.
“You did this, didn’t you, elf?” The head of the order demanded. “Your traitorous kind are in leagues with the vile undead, are you not?”
“My traitorous kind? MY traitorous kind? When you needed us, we came to your aid! We taught your kind Magic! We aided you when you needed us! When you called, we came! But when we needed YOU, where were YOU?!” Reign growled. “Where were YOU when the Sunwell was destroyed? Where were YOU when Sylvanas was killed? Where were YOU when we called for aid?! Where were YOU when the addiction consumed my people?! Do you have any idea what it’s done to my people?! Who’s the traitor?! You fucking morons don’t realize what you’re kind did?! The Sunwell was all we had to keep the addiction from consuming us! Kael saw no choice but to find other means! But even then, he took the strongest of us and continued to fight at your side! What did your kind do? Imprison us! Slay us! You deny us help in defending the sunwell , you deny our offer of aid, you kill us, then you have the AUDACITY to call US traitors when Kael turned in desperation to a way to save his people! Now here I am, trying to help save your godless city, and you accuse ME of BRINGING the plague?! My sister and most of my people died because YOUR people refused us aid against the Scourge, you fucking bastard!“ Reign was shaking with rage.
Marri couldn’t tell what he was saying. He was speaking common. But she could tell he was losing it. She reached out and placed a hand on his arm. Reign looked to her, calming as he saw the concern in her eyes. He took a deep breath and steadied himself. He turned to the head of the order again.
“No, I didn’t bring it. My kind are not allied with the Litch King. He is the reason we are in the state we are in. The fall of any major city, horde or alliance, to the litch king would be a disaster. You can see for yourself he has the plague. He needs out of here before more catch it.” Reign said. “If you’ll not allow me to take him out of here, first, I’ll kill him, so he’ll no longer be contagious. I can’t say if he’ll be a mindless slave of the Litch King or not. I almost hope he was. I’d love to see him rip you limb from limb. But I don’t know. I’ve never been faced with one who was undead then alive then undead again. Then, I’ll call for aid, and the horde WILL answer, unlike the allience. Thrall has honor, where as you do not. You’ll have so many horde up your ass, you’ll be coughing up war banners. We’ll take your city, and kill every last human, man woman and child. Better for them to die at the hands of the Horde, than to die of the plague. The choice is yours. Let him go, or the city will lay under siege and your innocent will be slaughtered.”
The head of the order was silent for a short time. He seemed to be attempting to determine if Reign was bluffing or not. Finally he seemed to decide he wasn’t bluffing. Not with the outburst he gave before. “Take him and get the hell out of here.” He said.
“Go tell them to clear the streets. As few people must be exposed to him as possible.” Reign said. The head of the order left quickly. He looked to Marri. “He’s grant us leave. Get him ready. This is going to be a long journey. We’ll be going to Undercity, but first we have to get to a city from where we can fly.”
“Where be de closest?” Marri asked
“I would say booty bay, but we can’t expose him to humans.” Reign said
“Dere be a outpost in Stranglet’orn. De Zeppelin stop dere.” Marri said. “It take days, but still be faster den goin’ on foot.”
“Agreed.” He said. Reign gave a whistle and Raze came running. “I need you to carry him, boy.” He lay Eroth over the back of the wolf. With that, they exited Eroth’s home and made their way through the streets of Stormwind and towards it’s exit. They ran into Prin and Windhorn on the way out.
“He has the plague?” Prin said.
“Yes. They were unable to cure it. We need to get him out of here.” Reign said.
Windhorn lifted Eroth off the wolf’s back and placed him over his shoulder. “Prin. I’ll be back. I must see Eroth and my friends to safety.” He said.
Prin blushed. “You’re... coming back?” She said.
“Yes.” He said not expecting the question. “I said I love you. I meant it. I plan to return... unless... you don’t want me to.”
“I’ll be waiting.” Prin said with a smile.
“Touching. Come on. Time is running out.” Reign said.
Windhorn nodded and they left the city. They made their way to Stranglethorn Vale as fast as they could, traveling day and night without sleep or rest. Finally they arrived at the Zeppelin. They boarded as soon as the sky ship had stopped. They rested below deck. Marri was the only one who didn’t sleep. Eroth was getting worse. She remained at his side, tending him vigilantly.
“Marri, you must get some sleep.” Reign said. “You’ll become ill if you don’t.”
“I be fine.” She replied.
“No, you’re not. I’ll take over watching over Eroth. You get some sleep. I’ll wake you if his condition changes.” He said, physically pushing her down. She protested but not for long. She soon fell asleep and slept the rest of the ride. Finally they arrived at Undercity. Windhorn scooped up Eroth. Reign woke Marri. They hurried off the ship and into the city. They made a b-line for Sylvanas.
She turned as they entered. She blinked in confusion. She stopped before her.
“Lady Sylvanas, we are in need of your aid.” Reign said, dropping to one knee. “Eroth, who you sent to Stormwind, was changed back to a human. But he’s dying of the plague.”
Sylvanas nodded. “Lay him down.” She said. Windhorn set him on the floor before her. Eroth moaned weakly. She knelt beside him and gently lifted his head. “You did well, Eroth.” She said. She took out a knife and plunged it into his heart. Eroth cried out in pain, then fell silent.
Marri screeched in shock. Sylvanas raised her hand to quiet Marri. Eroth began to thrash, Sylvanas was struggling to hold him down. He turned a deathly pale grayish-blue color. His eyes rolled back in his head and started to glow unnaturally and he shuttered as the thrashing subsided. He turned to Sylvanas. “My, queen.” Came a shuttering voice.
“The pain will pass soon.” She said. “Are you alright?”
“My lady! You were right! They’ve found a way to undo the plague but not cure it. We must watch them or they’ll bring disaster to the world.” Eroth said sitting up.
“Thank you for your services. You have done a great service and you will be rewarded for it.” She said.
“My life is to serve you, my queen.” Eroth said with a bow.
Sylvanas smiled and dismissed him. He stood, slightly shakily. He looked to Marri and smiled.
“What, no hug and kiss?” He asked.
She smiled and practically tackled him, kissing him lovingly.
“You did well as well, little brother.” Sylvanas said to Reign.
Reign smiled at her. “It is good to see you, sister.” He said. “Even if you do look like a Kal’dorai slut.”
“Don’t start.” Sylvanas said with a frown.
“Yeah yeah.” Reign said. “Can’t help it. That’s what little brother’s are for.”
“Scram, brat.” She said turning away from him.
Reign chuckled and returned to his friends.
________________________________________________________________________________________________________________

She didn't actual send him off to die. I'm just an angst whore, emo bitch.