Author's Notes:

A thing I promised to write a long time ago and only just remembered to post.

Tirek was pleased.

Celestia's pleading had reduced to animalistic growls even before the Rainbow of Darkness had finished its work, but her mind had remained long enough to give them the barest semblance of despair as she fought the remaking of her body. Fought and failed. He had watched the last dregs of conscious thought fade from her dull eyes until all that was left was his third and largest beast.

The conquest had been easy this time. They had thought him defeated and humiliated, stripped of his power and locked away for eternity in the pits. That complacency had cost them dear.

The one called Cadance had been the first to fall to his new spell. She was young and weak; pitifully weak in fact. The Rainbow had remade her in moments, its work complete before she could even think to react. A pity. He had thought of turning her against the stallion on which she had frittered so much attention and lust, but in the end the sight of his horror at the new shape of his beloved had been more than enough compensation.

Then there had been Luna. Powerful, to be sure, but timid. Once she had been a worthy opponent, a great goddess of the skies themselves, who alone might have been able to defeat him. Now, at the sight of him and the thing that had been Cadance, she hesitated.

It cost her.

Oh but she had fought, straining at the power he had unleashed with every fibre of her being, spewing profanity and curses at Tirek until the Rainbow had overtaken her voice, and then howling viciously to the very last. Her beast was anything but timid and even now strained at the chains that bound it to the foot of his new throne.

Then had come Celestia.

He had thought to send her former family to steal her away, but before he could do so, she had come to him. In full view of the legion at her back, she had offered herself to whatever he desired, if only Luna and Cadance would be returned unharmed. It seemed laughable; she must have known he wouldn't even consider the offer, yet Celestia had insisted.

Tirek's answer was to unleash the Rainbow against her. The opportunity to finally humiliate his erstwhile tormentor, to demonstrate his true power to the massed armies behind her, had been too tempting to ignore.

Perhaps she had hoped for it. Perhaps she had thought she might withstand the brute power of his weapon. At first it seemed she might, for powerful as Luna had been, she was nothing compared to the strength Celestia displayed. For stretched-out seconds she bore the full brunt of the assault, though her gasped moans of exertion soon showed how taxing the front had been.

Without warning her power had collapsed, plunging the Rainbow into the core of her soul. She had screamed then, wide-eyed but sightless, mouthing wordless pleas as her body was corrupted and remade from within. The words had found their voice when the first horn erupted from her head, only to be garbled once again by the tusks that cracked from her jaw.

She had fallen then, and now the guards watched, slack-jawed, as their former ruler writhed on the ground, each crunch and crackle of reforming bone and sinew sending waves of fear amongst their ranks. Then the beast that had been Celestia rose to its feet, its muscular forequarters glittering beneath the sheen of foamy sweat from its exertions, and lumbered to Tirek's side.