"Don't worry my faithful student, it'll be over soon. I can't guarantee it will be painless however," Celestia cooed as she heated up a railroad spike with a blowtorch. "All over soon."
"P-Princess! You must stop this!" Twilight cried, tears streaming down her cheeks. She didn't want this to happen - this couldn't be happening! This must be a dream! she thought.
"Oh thank goodness, I was worrying that this was real! I'll wake up any second now," Twilight reassured herself, laughing.
"Oh no Twilight, this is very real, I assure you," Celestia laughed evilly, putting a hoof under Twilight's chin to make her gaze meet Celestia's.
"B-But, this can't be real! Celestia would never do this!" Twilight shouted.
"I'll prove you wrong, my faithful student," Celestia levitated the glowing yellow railroad spike up in front of Twilight's face, the glowing metal reflecting in Celestia's eyes.
"What are you going to do wi-AAAAAAAGH!" Twilight screamed and writhed in pain as Celestia struck Twilight's flank with the glowing railroad spike. Twilight's now singed black flank throbbed with pain, grey smoke slowly curling away from it. Twilight's breathing came in shaking, shuddering breaths.
"Oh Twilight, the one thing I always thought you needed was" - Celestia cackled as she struck Twilight in the jaw with a hoof - "a higher pain tolerance."
"You-You-You're a monster!" Twilight spat in Celestia's eye.
"Please do not do that again, Twilight," Celestia coldly replied as she struck Twilight's flank again with the red hot metal, this time holding it to her flank for a few moments. "That would make me angry. Don't you want to make your teacher proud, Twilight?"
Twilight screamed. She screamed as loud as she could. The pain was unbearable; she had never felt such intense, constant pain in her life. The worst part was no matter what, the pain didn't stop. The smell of burning hair filled the room, the red hot railroad spike having melted her coat away, leaving a charred black spot where her Cutie Mark once was; smoke slowly curling away.
"You're screaming already? We're just beginning!" Celestia cackled as she heated the metal once more, applying it to a grinder to sharpen it down to a fine point. The room they were in was a mundane tool shed, vices, drills, saws and torches everywhere. The room had a particularly earthy smell, almost like that of Sweet Apple Acres.
Sweet Apple Acres, Twilight thought. Am I ever going to be there again?
Celestia finished grinding the railroad spike down to a fine point, the clunky squareness of the metal slowly turning into a fine conical point, and turned to Twilight (who was bound to a chair).
"Why would you do this? What did I ever do? Tell me Celestia, if you are going to kill me, tell me why!" Twilight shouted, tears flowing from her eyes freely. Her body was wracked by sobs, she was shaking. Her Princess - no, her mentor doing this to her? Unbelievable!
"Oh, Twilight. You never did anything. I just simply like to see ponies in pain," Celestia spoke softly and calmly, as if talking to a child, while she stroked a hoof through Twilight's mane. "Can't you see Twilight, I'm a sick and sadistic bastard. Why would I have made you go through all of that as some mere 'test'? No, it was because I enjoyed watching you suffer through it. I could have stopped it at any time, but I was genuinely enthralled."
"If you're going to kill me, just get it over with!"
"With pleasure, my faithful student," and with that, Twilight was killed. Her mortal coil relieved by a red-hot piece of iron piercing her flesh like hot butter, coming to rest inside of her left lung, the tip of the metal touching her heart.
"It was a pleasant time, but I've grown bored of your shenanigans," Celestia coldly replied as she pulled the iron from Twilight's dead body with a loud squish. Celestia levitated up a shovel, and dropped the spell that warded the shed of sound.
None must know, she thought.
~~== Later ==~~
The deed was done, the grave dug, body buried. For a brief moment, Celestia felt a pang of regret. Only for a moment however. There were more ponies to be eradicated.
"Sister, how art thou?" Luna asked, trotting over. "Where hast thou Regalia gone?"
"Oh Luna, I didn't see you there. I was just going for a stroll before I set the sun," Celestia replied, putting on a fake smile. Celestia wanted to end the life of her pitiful sister.
"Ah, We see," Luna replied. "Why do thee have a shovel?"
Celestia nearly broke into a sweat, but quickly thought up a lie: "I was removing a dead shrub."
"Ah. We-I see. Have the worms been getting at the rose bushes?"
"I'm afraid so. However, I have something important to speak about with you. It concerns Twilight," Celestia lied, feigning sadness. "She, she doesn't want to be my student any more."
"Oh, sister. Where hast Twilight gone? I wish to speak with her," Luna replied, hugging Celestia.
"Luna, she's already left us," Celestia sniffed. Luna hugged her tighter.
"When did she leave?"
"She left not but an hour ago. I was taking a walk to calm myself and think."
Oh woe is me! Feel bad for me, *sister***, Celestia practically spat the word "sister" in her mind.
" 'Tis alright sister," Luna reassured Celestia, nuzzling her.
"Oh Luna," Celestia whispered, a single tear rolling from her eye onto her cheek.