Love these ideas, all of them are very good ones 
I can pop this post if you want on the top one as an important post to keep note of!
I haven’t actually had experience with that yet, to be honest 
Which is odd, because you’d think I would.
Alrighty, well time to tackle this challenge, oh boy. I went back and read about Kael’thas, and needless to say, this scenario would be much, much more dramatic than that clean cut one. Inner turmoil indeed. Now, you’ll see why.
The Rise of Blood King Kael'thas
A lonely necropolis floated along the abandoned scourge fortress formally known as “Temple City of En’kilah”. Not many mortals dared to visit there, as there were rumors of tormented spirits wandering about this place of which attacked anyone and anything that dared get too close. There was some justification to these rumors, for this was the home of the San’layn, of whom had hidden themselves for over a decade after Arthas’s fall.
One lone Sin’dorei made her way across the icy terrain, staring up at the looming gate of the city. She shuddered in fear but pressed onward. Bouncing along her side as she walked was a bag filled with something rounded and hard. She had to deliver this object to these people, otherwise, well. There would be no hope left.
She’d heard the rumors of the Ren’dorei and how they planned on attacking the Sunwell with a large group of the Alliance. There was to be no mercy. Intel told her that the Horde forces were focused upon the warfront in many other areas, and not many paid her any mind when she tried telling them about these attacks. She was just an apprentice. What did she know?!
Unfortunately, The Shattered Sun Offensive had fallen to corruption and politics over the years. The Sunwell was restored, yes, however methods on how to properly protect it from falling into the wrong hands were a constant debate on everyone’s lips. The rift opened further at the shocking betrayal of the Ren’dorei, too. Their own people, not understanding the apathy of the Alliance. At least the Horde stuck together, outcasts just trying to survive. Well, that was before the warchief’s reign, that is. And that’s what was creating the second rift.
Two sides held onto this story. One in firm belief that Sylvanas would come to their aid should the Sunwell be attacked. The other under the belief that she would most definitely not help, and potentially even use an attack to her advantage to raise undead Sin’dorei even if Lor’themar protested. Ah… Lor’themar. He was going against her too, which just ripped things apart even more.
Which all lead up to this. Fae’rine Brightfyre closed her golden eyes, recalling the time where she’d been approached by that terrifying elf.
She’d been in Nazmir, casting blood magic to fight against the Alliance, but unfortunately her camp had been ambushed. They fought long and hard, but it hadn’t been enough. Cornered, she was ready to die.
But death never came. Among the last of the blood mages to have survived, she bore witness to something peculiar. A cloud of bats converged together to form a tall elf with deep red eyes, bat-like ears, and gleaming fangs when he snarled. She shuddered in fear as she saw him rip to shreds every single Alliance solider that had her trapped. Then, he turned to her, Blood pouring from his lips…and held out a hand.
“It appears as though you needed a little bit of help, dear,” Blood Prince Theraldis purred. She didn’t take his hand, rather stared at it in confusion. As far as she knew, all of the San’layn had been wiped out many years ago. This was coming upon her as a huge shock. Her eyes stared into his, and she remained silent for just a moment.
“Is it really you?” she finally whispered, her voice broken. Slowly, the Blood Prince gave a nod.
“Yes. We must hurry,” he replied. Fae’rine was absolutely stunned, and Theraldis wasn’t about to wait. He lunged at her and swept her into his arms, teleporting away to where it was safe, away from all of the action. Placing the terrified elf upon the ground, he stared her down. “Let me explain, Fae’rine.”
As it turned out, Theraldis had gone off to the Northrend front with the other forces of Blood Elves fighting for their city by joining Illidan against Arthas. He’d been slain and risen, presumed entirely dead, for he never showed his face during the Northrend campaign, not even once. Only the champion knew of him, and that was from a vision. When he fell, he left at home a wife. That wife was Fae’rine. She’d given up hope that he’d survived long ago, and dedicated her life to fighting for her city in his name. Well, this was quite the surprise, then.
Theraldis had fallen before Kael’thas had displayed his insane behavior, whereas Fae’rine had seen it all. For months did they argue back and forth, then, about the intentions of the fallen prince. Fae’rine had joined the Shattered Sun Offensive to protect the sunwell, serving a while before joining the army due to growing tired of the rifts and corruption. She didn’t want to believe Theraldis’s words. Finally, though, did Fae’rine begin to see eye-to-eye with him. She really didn’t want to accept it. But, well, she did. And she was the key to something really, really dangerous.
Kael’thas. How could his behavior be justified? Illidan was brought up time and time again, but Fae’rine told herself that he wasn’t nearly as corrupted as the fallen prince. So why was she standing here, gazing at the nest of San’layn, with his skull in her bag for a ritual to bring him back?!
Well. Deep down, she trusted her husband. She knew his intentions were for their city. He told her that Kael’thas was corrupted by the fel, but like a phoenix, would be born anew in this ritual. He would be a Blood King. What did that mean? He would be like Lana’thel? She shuddered at the thought. But upon looking into the eyes of Blood Prince Theraldis, she knew that he was right in the mind. More violent, more brutal, and extremely bloodthirsty. But…loyal to his city. He’d never risen a hand against her. Not even when she shouted at him that he was wrong, that this plan would never work. He remained calm and talked to her, trying to get her to see from his perspective. It worked. Here she was.
From behind her, Blood Prince Theraldis appeared. A hand fell upon her shoulder, and she shuddered, jumping in surprise. A soft chuckle sounded in her ear. “Have no fear. You are safe here, under my order. Trust me, Fae. I want what is best for our people. We are stretched too thin. The Reagent Lord has unknowingly given intel on how to breach our city to the enemy by working with them. My bats have caught the whispers of the Ren’dorei plans. We haven’t much time.”
The Sin’dorei flicked her ear, strands of her brilliant red hair glowing as the sun set in the horizon. Finally, she nodded. “Alright. Take me up there,” she sighed, holding the bag tightly to her chest. Theraldis gave a kind smile and took her into a hug. However, blood dripped onto her cheek, causing her to shudder. “…I assume you’ve just eaten?”
Sheepishly, Theraldis cackled. “Why, yes. Wouldn’t want me losing control and ripping your throat out now would we? Come. You can join us if you’d like, as a representative of Silvermoon City.”
“I will be seen as a traitor, Theraldis,” she replied in a broken tone.
“No,” he purred softly. “Some extreme measures must be taken for the protection of our people. Silvermoon City has no idea the danger it is in. But we do. And we will not allow our city to fall.”
From here, Fae’rine took the hand of her husband and allowed him to bring her up to the necropolis, and boy was it a sight to behold. Gargoyles flew about, their wings tinged with blood, as if permanently stained. San’layn Neophytes, fresh from having fallen and being raised from the front, were being trained by Blood Marquis and Marquees. Banners of the San’layn sigil were draped everywhere, and regal carpets littered the floor, along with crystals of blood. Various blood orbs held on pedestals glowed menacingly, filled with the fresh crimson liquid of their victims and stored for later consumption.
All in all, this area was extremely regal and haunting at the same time. Theraldis lead Fae’rine to the center teleporter. The other San’layn in the area turned to stare her down almost hungrily, but at a steely glare from the Blood Prince, adverted their gaze. Together did Fae’rine and Theraldis approach the center of a large ritual room, where corpses were strung up by a great amount. Elves, not having been used for San’layn and slain by being cut down on the front by the Alliance, would be utilized for this. First, their new blood king needed a body.
Standing there at a ritual table was the warchief herself. What?! Fae had no idea she was involved… Next to her was Blood Prince Atherann and Blood Prince Dreven, of whom had his body retrieved and brought back by Sylvanas after the unfortunate run-in with the Alliance. The warchief smiled ‘kindly’ upon seeing Fae’rina.
“You managed to obtain the key piece to this puzzle, hero. Good. Our army will be extremely powerful with the addition of the San’layn,” she mused, nodding in approval.
Atherann’s glare locked upon the warchief, and he said without pause, “You are sure this process will aid in the protection of our city and people, warchief? We do not want our Blood King to be raised just to be ordered away for other purposes.”
Chuckling, Sylvanas nodded. “Why, you have my word, little bat. Your city will be safe. My army, of course, will be even stronger with your aid. You know my price. In exchange for my service, I need soldiers. Powerful San’layn to be risen and utilized on the front.”
“We are not tools for your use, Sylvanas,” Dreven growled defiantly, but this only caused the warchief to snicker.
“But of course not. You would do well to listen to my order, however, as your people rely upon me entirely. You will always have your will, and can always refuse to do as I say. But I cannot promise protection in every scenario if you do not obey. You are your own people, you will protect your city. But you will also serve me,” she replied. This caused the three blood princes to go silent.
Fae’rine was uneasy about this. More and more did she hesitate, until finally, she took a step back. “No. This is a terrible idea. I should have never gained the Offensive’s trust, I should have never stolen the skull away when they were busy arguing as they always do. I am betraying my city. Something is amiss here. But I can stop it, here and now!” Suddenly a shield of arcane surrounded her, and she stepped back, chanting a teleportation spell. The entire room froze–action needed to be taken here and now. Atherann lunged for her, but Theraldis cut him off, hissing loudly.
“FAE! NO! Please… this is our only hope. You have to trust me. Please,” the Blood Prince growled, staring her down as she began to reach the final words of her spell. Meeting his eyes, Fae paused. The spell slowly dissipated in that moment–a moment’s pause was a pause too long. That’s when Theraldis lunged for her, pinning her down and snatching the bag away. He tossed it behind him, where Atherann caught it and set it upon the table.
Fangs plunged into Fae’s neck as she cried out, slowly being drained. Theraldis didn’t kill his wife, however. He weakened her considerably before dragging her off, placing her into a cell and wiping his lips of her blood. Weakly, she stared at him, betrayal glimmering in her eyes. “…I’m sorry,” Theraldis sighed, but straightened up, a cold glint in his gaze. “But you cannot interfere, Fae. I will see you soon.” That wasn’t reassuring for the poor Blood Elf. But he had no time to dwell.
Returning to the ritual site, Theraldis noticed that Sylvanas looked less than amused. “Pitiful girl, thinking she has any power here. That minor upset will do nothing, however, not a thing at all.” She looked over to see Nathanos approaching, bowing to her and holding out a dagger. The warchief accepted it, approaching the table with the skull.
Now, the ritual began. Only the skull was needed here–besides, the rest of Kael’thas’s body was lost. But that mattered little. The flesh from the dead elves hanging on the walls began to coagulate and ball up. Slowly did it creep toward the skull like a bunch of hungry maggots, latching on and building something new. Taking on the biological data of the body, the flesh began to modify itself into Kael’thas. This took several minutes of fleshcrafting until finally he was complete. His skin was abnormally pale, and he had a very large hole in the center of his chest, where the fel crystal used to be. The residue of his corruption, of course, could still be seen in that case. His hair was purely white, having lost all of its color entirely. Not one strand of it was golden any longer.
Off to the side, a Val’kyr groaned and fell to the ground. The fleshcrafting has used all of her power, and just like how Nathanos was restored, used up yet another one. However, just like when Nathanos had been restored, she was not entirely dead, rather likely out for the count for many years. Just so, she might as well be. There was no relative required for this sort of fleshcrafting due to a different ritual occurring, however, very soon. This is where the San’layn came in. They needed a new ruler, a Blood King or Queen. A simple forsaken, though powerful, would not do. No, they needed a master of blood. Kael’thas was simply perfect for this ordeal, as he had originally been their leader back before they were slain.
Now, it was Dreven, Atherann, and Theraldis’s turn. Slowly did the Blood Princes approach, raising their clawed hands upward. The blood orb that had restored the previous Blood Prince council had been obtained, but this time injected with much more potent blood magic. Everything had come down to this. All of the remnants of fel would be flushed away and replaced with blood magic, for he was to be king.
Tendrils of blood lashed out of the orb, attaching to the body of Kael’thas. Slowly did he begin to mutate… for the vampyr curse, especially one this concentrated and potent, was a mutagen. And my goodness, it was glorious.
From his back ripped out a new formation of bone, spreading out to form limbs of a new kind. Wings, giant bat wings, spread out, stretching and contracting slowly. His lips opened widely, and all of his teeth sharpened into points, his canines longer and more deadly than the rest. His nails shifted into long, dagger-like claws, dangerous weapons to disembowel his enemies if he wished. His ears became wider and more bat-like, some flesh ripping and tearing from this process and chunking some bits of it, as this wasn’t perfect. He was therefore left with ripped ears. The center of his chest filled with blood, but it still wasn’t completed with pure flesh. Rather than a gigantic fel crystal, a huge orb of blood formed swirling forever in that area.
Then, slowly, his eyes began to open, as the blood curse pulled his very soul from the Shadowlands. These eyes were purely black, the eyes of a hungry predator, wanting to strike and devour whatever he could get his claws on. Despite being undead, there was almost a life-like glint to this dangerous, pitch black gaze. A look that was starved and very much wanting to gorge. Slowly, he sat up, his wings opening gloriously for a moment before draping down, quite like Lana’thel’s had at rest. Slowly he looked about, many strands of his pure white hair falling into his face. His mouth was partially opened as he appeared to breathe out of habit, though he needed to take no breaths. A long tongue lashed out and swept over his fangs. He was hungry.
Theraldis did not hesitate to hold out a broken blood orb to him, offering him blood. The Blood King accepted it and began to drink…and drink… and drink. His hunger was not sated with just one. After having gone through several more, finally, he spoke. His voice was soft, tired, and cold.
“Well well well. It has been a while, hasn’t it?” he chuckled. “It appears the only setback was not just Tempest Keep. What have I been made? How is it that I can think so clearly… my head is not fogged with madness… only hunger, at first, which is sated for now?” Around him did three orbs of red float. One over each shoulder, and one over his head. He would be given royal black and red robes for proper garb, much darker than he used to wear, soon enough, to complete him.
“You are the new Blood King of the San’layn, of whom are quite loyal to you, Kael’thas,” Sylvanas replied, and approached him, leaning into his face. “Therefore, you are owned by the Horde. You are owned by me. You will have your chance to protect your city. But dear little bat, I hold the chain.”
The Blood King paused, and the Princes looked quite concerned. Slowly, Kael nodded. “Understood, Banshee Queen. For now. For now.” This was followed by somewhat of a dark cackle.
The Blood King had risen, and soon blood rain would pelt the Alliance in ways that they’d never seen before…
(End)
So, whatcha think Kael’thas fans? Blood King Kael, as you requested. Now, I know me bringing the warchief into this is a bit dark, but hear me out. We see reflected in this story that the San’layn are willing to work with her, but they have free will, and they will be making their own decisions. As such, well. If they do not agree with her, and if she betrays them, she won’t be able to properly yank the chain. Their objective is to protect Silvermoon and gorge upon their enemies. Who’s to say the warchief will hold up her end of the deal if she does end up going off the deep end? And if a turn of events happens, and she ends up somehow being a good warchief for the Horde in a twist, they’re already on her side in a way.
Also, I use a different setting in this scenario than the last one, just to spawn more ideas and such, because either Naxxanar or the Old Kingdom in my opinion would be really cool spots for the San’layn hub to be.
Also I think a crown of sharpened bone would look really cool on the Blood King
FOR THE IMAGE OF BLOOD KING KAEL GO HERE AND SCROLL DOWN!
San’layn/vampyr elf Customization (and Allied Race idea) Coagulated Megathread {Re-VAMPed} - #3642 by Fallynn-wyrmrest-accord