A Conversation at Arms Length
Chains rattled in the dim hollow that was Tartarus, and Tirek growled as he looked over his bindings once again. Cursed, vile ponies, he mentally railed, as once again he found no chinks, no weaknesses in either the physical chains nor in the magic woven into them and the very rock they were attached to.
I was so close! He thought, angrily, as he yanked an arm back in spite, only to see the taut chain halt the limb before it could move very far. I almost had everything I needed to make this the single easiest conquest in all of history! And just one, stupid, pony was all that kept me from securing my freedom, my place of power... and my revenge against my so-called “brother!”
Tirek's memories of the events just past still roiled in his mind, and despite his weakened form he snarled loud enough for the sound to echo in the pits of Equestria's most secure prison. I'll get out again, I know it. Even if only when they arrive, and the chaos that will ensue. It will be tricky to avoid being executed for treason, but if I'm quick I might—
Further thought was cut off as a flash of magic erupted not far in front of him, and Tirek winced as his weakened state made even such a trivial trick potent enough to blind him momentarily. Soon enough, however, his vision cleared, and he snarled again. “And just what are you doing here, you filthy horse?” he demanded of the figure that had teleported in. “Is my defeat by your ally not enough? Or perhaps,” he added, in a lower tone of voice and a condescending smile. “Are you finally indulging in the finer things of life, such as gloating over a defeated foe?”
Celestia, alacorn princess of the sun, one of the ruling diarchs of Equestria, merely returned a level gaze at Tirek's taunting. “You never give up, do you, Tirek?” she asked, in a voice as flat as any mortal could produce. “Even now, mere days after your defeat, filled with anger, you still seek to corrupt.”
“It's not as if I have anything better to do,” Tirek replied, with an insidious smirk. He waved his arms as far as they could move over the bare, rocky pit he was chained in. “Your skills as a hostess leave quite a bit to be desired.”
The pony merely kept her gaze on the Tirek, and the two stood there in a silent contest of wills. How long neither could say, but eventually the grin slipped off of Tirek's face, and he scowled at the princess. “Well, what is it you want then, if not to gloat?” he brusquely demanded.
“Why didn't you leave?” Celestia quietly asked. Her voice was so low that Tirek almost didn't hear it, but there was little else to hear in this part of Tartarus, and so he nevertheless understood her perfectly. “You had all of our power, all of our magic. You had us beat. You could have gone back to your people, but you didn't. Why?”
A silence fell over the pair for a moment, though it was soon broken by a harsh, wheezing laugh. Tirek's laughter grew quickly, and soon he had to throw his head back and howl in merriment as a confused look spread over Celestia's face. Her confusion soon gave way to angry embarrassment, and she began to charge her horn. “If you won't take my question seriously—”
“Did you think that they would only send my brother and me?” Tirek suddenly asked, as he snapped his head down to stared into Celestia's eyes. His own orbs burned with hatred and, surprisingly to Celestia, fear. “Did you really think that if they wanted this world that they would only send a pair of demons, and not a full invasion?”
The alacorn frowned, and her magic dimmed away as she dropped the teleport spell she had begun to cast. “Then why did you and Scorpan come to Equis?”
Tirek snarled at the name, and his body attempted to lunge out of reflex. The chains held him easily, however, and he soon regained control over himself, though Celestia was astounded as his expression somehow become even more foul. “We grew tired of always being second fiddle to his chosen favorites,” Tirek replied, and then spat to the side. The rock sizzled where his spittle landed, but he continued to speak. “We wanted a world for ourselves, to corrupt in our image, to start our own crusade! And it would have worked, if not for your filthy 'friendship'!” Tirek heaped scorn upon the last word of his sentence, and his brows furrowed as he concentrated more of his hatred towards the being in front of him.
Celestia could only stare at the beast for a moment, and then sadly shook her head. “No wonder his defection hurt you so,” she said, quietly.
“SHUT YOUR WHORE MOUTH!” Tirek roared, and the room shook with his volume. Even knowing how secured he was, Celestia found herself stepping back out of reflex. “You know nothing, nothing about what drives me! You pathetic, demented tool! You warped, fleshy sack of water! That Scorpan betrayed me was almost to be expected, but not why he betrayed me!” His voice dropped as he threw insults at her, but the heat and the hate never left it as Tirek continued to speak. “He knows, just as assuredly as I do, why we do what we do! And he turned his back on it! FOR YOU!” At this the demon attempted to lunge forward again, though Celestia saw it was a half-hearted attempt, more out of principle than any real loss of control or bid for freedom. He chains jerked him short, and they briefly flashed with a golden light before the monster calmed himself again. Then, after a moment, he began to laugh again. This time is was not the genuine, startled amusement at a mistaken thought, but the slow, callous mocking of ignorance. “And in the end it will be his destruction, as it will be yours!”
“And how do you figure, Lord Tirek?” Celestia asked, finally placing just a hint of sarcasm at his assumed title.
Tirek, however, merely smiled at her, and his wizened, drained features couldn't rob the expression of its menace. “Because nothing will stop our people from finishing what they started,” he said, almost calmly. “Every world will burn, every corruptible fleshling will rot, and their souls will feed the war engines of my people. Sooner or later, the Burning Legion will come for your world, princess,” Tirek sneered, and then laughed once more. “And when they come, Sargeras himself will crush you like the weakling you are!”
He began to laugh again, and this time the raucous, mocking noise filled the cavern around them. Celestia frowned, and then began to charge her horn. “We shall see about that,” she countered, and then flashed away in a teleport.
Tirek only laughed harder. And somehow, despite the distance now between them, Celestia knew that he did.
Author's Note
A small thing to work on the writing juices. And also hopefully to excise the urge to start yet another long-winded story that will take a century to finish. 
