"The Council of Starlights welcomes you, Celestia."
Celestia struggled against her ropes. "You'll never take this nation for yourself, Starlight," the alicorn spat, earning another boop. "I won't let you."
Lead Starlight of the Great North shook her head, chuckling to herself. "Oh, dear, dear Celestia. My, how far you have fallen! And it has hardly been even a month since we did to your sister what we're about to do to you."
"You leave Luna out of this!"
Chairmare Starlight, heir of the Chair Realm, was the next to respond, flashing a sinister grin as she clapped her hooves together. "Guards, bring out the prisoner if you please."
A metallic grinding noise filled the room as a large steel hatch yawned open behind the Council of Starlights. Former Princess Luna was led out in a straightjacket. The madmare's eyes met Celestia's.
"Hm," Starlight the Third, underling of her Superior Starlights hummed, "I'd run if I were you."
Celestia's eyes shrunk to pinpricks. "Wh--"
"LAVA!" Luna screeched, lighting her horn and unleashing a blast of molten rock. She stomped her hooves on the ground, shooting upward on her newly-summoned elephant boots. "FOR TOO LONG, SISTER, CANTERLOT HAS REMAINED COLD AND FRIGID IN THE WINTERS. I AM HERE TO CHANGE THAT NOW. WITNESS ME, AS I TRANSFORM CANTERLOT MOUNTAIN INTO CANTERLOT VOLCA--mmphf!"
Starlight the Third tightened the rope holding Luna's mouth shut as the Chairmare replaced the anti-magic ring on the former Princess' horn. "As you can see, Celestia, we have things all under control. We have no need for you here..." a smirk grew on her face. "Equestria has no need for you here."
"No--"
"Yes!" Lead Starlight cackled, "The Starlight of this realm made a fatal mistake when she accepted friendship, and thus, we, the Council of Starlights, have ruled that we shall carry out her intentions in full ourselves. Guards!"
More steel hatches opened all around the room. The entrance hatch slammed shut, plunging the corridor into darkness for a moment before a dull, crimson light illuminated the walls. Celestia wriggled in her ropes, which the guards standing beside her responded to with another boop. Golems of stone emerged from the hatches, descending upon the Princess.
Luna's cackled muffle grew silent as she was led away once more. Celestia felt one of the golems grasp a hoof, anchoring it to the ground.
"What are her intentions?" Celestia seethed, kicking away the golem with a free hoof. The sickening crunch of it shattering against the wall echoed through the metal-lined room. "And where is she?"
"The Starlight Glimmer of this realm wished to abolish cutie marks," Lead Starlight of the Great North stepped down from her throne. "She was defeated, and ultimately... reformed by that student of yours, Twilight Sparkle." The mare snorted. "But that is beside the point. Twilight is gone now, as is this realm's Starlight. We the Council shall carry out this original wish in her stead. Starting with you, of course."
Lead Starlight lit her horn, joined quickly by the two other Starlights by her side. Their pooling mana swirled overhead, coalescing into a thaumatic tornado that inched closer to Celestia by the second.
"Hm, I wonder what you're going to do now?" Chairmare Starlight held her grin. "Oh wait, you're going to do nothing. What a weakling. Always relying on others to do the dirty work for her. Just like the Celestia of my realm."
Celestia's eyes widened as the magical whirlwind condensed into a solid bolt of mana, aimed directly at her flank. She looked to Lead Starlight, finding only a pleasant smile where she'd expected a murderous grin.
"Thank you for the cutie mark, Celly."