Canterlot, Night
Celestia shot upright in her bed and screamed. At once, several guards rushed in to see to her, though they saw nothing amiss. After about a second, Celestia's shrill shriek petered out, and she was left sobbing.
One of the guards tentatively approached her. "Princess?" He said. "What... what's wrong?"
Celestia didn't respond, instead choosing to roll onto her side and continue crying. The guards looked at each other in confusion, unsure of what they should do.
One of them approached the princess again, still unsure of what was going on.
"Princess... please. Tell us what's wrong." They said. Celestia lifted her head slightly, and softly said a single word.
"Luna..."
Hollow Shades, Night
Jason watched, mouth agape in horror as Luna's body slowly bled onto the ground. He fell to his knees. Her head lay in front of him, its lifeless eyes seeming to stare into his soul. He reached to pick it up, but was stopped by a loud thud from before him.
Luke stood there, guitar over one shoulder. He extended a hand and wisps of shadow extended from it, gently coiling around Luna's body and head. Jason stood up.
"No." He said. "Luke, you can't be doing this. You just... murdered her for no reason."
"No, I didn't." He said, his voice mixed with that of the Nightmare. "She had power, and I wanted it. There's your reason." The shadows suddenly tightened, and dragged the corpse over to the Nightmare. They wrapped around it like a cocoon, and suddenly melted, leaving only a tar-like substance behind, though it retained a silvery sheen. Luke raised his hand, and the liquid flowed into him.
Suddenly, he grunted in pain. He doubled over as his back began to bulge and his clothes ripped, and shadows seemed to dance at his feet. With a sickening sound like the tearing of flesh, two huge bat-like wings erupted from his back, flicking off any blood that remained on them. He groaned again, and slowly a spiral horn emerged from his forehead, glistening in the moonlight with gore. The shadows leapt up to his body, writhing over him. Softly, a sound like the clinking of metal could be heard. When the shadows retracted, Luke was left with a pale blue armour covering his body. He raised a gauntleted hand and clenched it.
"So, this is the power of an alicorn." He said. "Not bad. Not bad at all."
Jason watched the proceedings, frozen in fear. He finally managed to find his voice, only for nothing but a choked sob to escape his lips.
"Luke..." He said. "Is this really what you've become?"
Luke chuckled. "What else would I be, Jason?" He said. "And this is only the beginning. Soon, all of Equestria shall kneel before me."
"No..." Jason said, shaking his head. "No! You can't go and do this, Luke! You have to see reason!"
"Hmm... Nah." Said Luke. "I think I'm still going to go ahead and conquer the world."
"...I can't let you do that." Jason said.
Jason leapt at Luke, hands blazing. He threw a fireball into his face, before grasping his arms and pouring as much energy as he could into his fire, intending to burn Luke down.
Luke merely laughed, shrugging off Jason's attacks and head-butting him in the face. Jason crumpled to the ground.
"You can't fight me, Jason." Luke said, chuckling. "Not like this. You're far too weak. Why, you're not even worth the trouble of killing. I'll see you around, but for now, I'm going to absorb the rest of those ponies."
Luke spun on his heel, before leaping into the air in the direction of the battlefield between the cult and the guards. He landed amidst the melee with a crash, and slowly all of the combatants turned to face him. A cold smile parted his lips.
"Kneel." He said, his voice oozing authority. As one, the cultists sank to their knees. The guards, however, charged at him. He grinned, and struck a chord. The wave of energy that washed over them sent them all to the ground, tumbling end over end in the dirt. Luke laughed at them.
"How a species as weak as you ever became the dominant one of this planet, I will never understand." He said. "But no matter. I need not understand to destroy."
Luke raised a hand toward the ponies, and hundreds of shadow tendrils shot toward them, ensnaring their legs and constricting their bodies. Luke laughed as they began to melt into a tar-like substance and flow toward him.
Canterlot, Morning
Jason woke with a start. Looking around, he saw that he was in the Canterlot hospital. He groaned, feeling his head where Luke had struck him. He was just thankful that he hadn't been hit with his horn. A nurse approached him.
"Good morning, Jason." She said softly. "How are you feeling?"
"Like shit." He said, shaking his head in an attempt to clear it. "How did I get here?"
"You were recovered by some guards sent to investigate the aftermath of the battle... We're so sorry about what happened." She said, looking down.
"What... happened...?" He said, before gasping. "Luna! Oh sweet Jesus, I need to tell Celestia!" He all but leapt from the bed before the nurse stopped him by putting a hoof on his chest.
"She... she knows, Jason. When Luna... died, Celestia sensed it. She's been inconsolable since." Jason slumped back down at her words.
"I... I failed her." He said. "I failed them all."
"No, Jason, I'm sure you did everything you could." She said. "In any case, Princess Celestia would probably like to see you. You were with Luna at the end, and, to be honest, you're probably the only one left alive who knows what happened there."
Jason drew in a shuddering breath, before steeling himself and sitting upright. "Alright." He said. "I'll go talk to her. If I can help her to cope with her sister's passing, then its the least I can do."