With a whisper of sound, the rainbow came down, all pretense of it's friendly presence lost in the night.
Earth ponies scattered madly in all directions as the ribbon of multicolored light reduced another wattle-and-daub cottage to fragments of burning straw and kindling. Most kept moving after the impact. A few lay very, very still.
If they weren't too badly injured, that was for the better. The monster preferred moving targets. She moved forward on denim-clad legs, leather boots covering her feet as they squelched through the winter mud. With a gesture, the glowing arc whipped stinging sparks across the flanks of the fleeing crowd, herding them together into a milling mob of panicked, whinnying fear.
Once the running ponies had been crowded together closely enough, the rainbow became a fence of prismatic menace, burning the stragglers with the occasional runnel of liquid sparkles as it followed it's mistress towards the mountains with the population of the town. And every pony knew that to enter the hills with the monster was to never be seen again.
The *crack* of an ebon-shod hoof on the beast's shoulder sent it tumbling to the ground, downed but not out as the rainbow released it's prey to scatter into the hills. Coiling, it struck like a serpent, fangs of light snapping at the winged tormentor who dared to interfere...but inches away from tearing into a cresent-mooned cutie mark, the cheerfully colored menace was swatted aside by a thin column of flames.
A second challenger appeared, banishing the shadows of the late evening with a nimbus of morning sky.
"No more, eldest sister!", Celestia cried.
The two-legged thing opened eyes that had been bleached nearly completely of their original blue and let it's mouth hang open. A voice that had never known or needed flesh rolled out between slack lips like a cloud of menace.
"TOO LONG HAVE YOU HELD THE PROPER MEETING OF LIGHT AND DARKNESS AT BAY, YOUNGEST. I SHALL END THIS IMPURITY OF FLESH AND RETURN THINGS TO THE PROPER, CLEAN RADIANCE OF SPIRIT. ONE HOST, SIX, THOUSANDS- UNTIL THESE MATERIAL THINGS NO LONGER HINDER US. THE SIN OF FORM SHALL BE ABSOLVED IN MY LIGHT."
"We say thee nay, Alexandrite! No more will you harm another living-", and at harm, the ribbon of colors struck again, coiling itself around Celestia to crush the alicorn to a shapeless mass of flesh. Luna pounced on the rainbow's tail with all four hooves, pinning it to the earth before it could reach her sister. Before the other end could rise again, Celestia's forehooves crumpled it, flattening the true evil into a technicolored carpet splattered with the muck of the hill.
"Release the girl, Alexandrite and return to thine prison.". Luna's horn sparked, a cresent sickle of moonlight forming at the end as she ground the thing further into the unyielding earth. In response, the living rainbow began to heat and bubble.
"ENOUGH. CLEARLY, WE MUST BEGIN BY BURNING YOUR CORRUPTED FORMS FROM THE REALM. WHEN WE HAVE REFORMED IN A THOUSAND YEARS, YOU WILL UNDERSTAND REASON AND COMPLY."
Celestia's mouth set in a grim curl and a small sun joined the crescent of focused moonlight. With a convulsion of mystical energies, the two forces tore the melting rainbow apart like a twist of taffy, interrupting it's attempt at self-immolation. Two pieces of colors mixed and writhed on the hill like a broken-backed constrictor, alive but crippled. The beast fell to it's knees, it's hat tumbling down the hill. Golden hair spilled out, only to be stained by the gout of blood that splashed from her nose to stain both hair and vest. Hidden beneath it, a heart-shaped locket cracked nearly in two and hung loosely from it's chain.
"Release thine host or we shall do what must be done, eldest.", Celestia said to the wounded, mad thing.
The bisected rainbow threw itself against the glowing prisons that encased it, cracking the shells of aura and sending a wave of creamatorium heat into the sky. The golden hair dried in an instant and curled at the ends as an errant wisp of energy caressed it, leaving ugly brown stains of dried gore to color what had once been a country-girl's riding outfit.
"ALL SHALL KNOW MY LIGHT AND BE FREED.", the obscenity that coiled at her breast bellowed.
With that, the two alicorn's heads jerked twice, like a neck falling into the hangman's noose. The two already-torn pieces found themselves each ripped anew, not once but twice- and finally fell limp, the bright colors congealing into grey hunks of calcified, monochrome stone. At the girl's chest, the broken locket mirrored the gesture, disintergrating into six jagged shards of useless metal- and the light in the child's eyes extinguished itself like a burned-out lightbulb. The puppet collapsed, it's strings cut- and no life remained within it.
Darkness fell once again to it's natural place, clouds forming as the burning heat faded away. One pony galloped through the beginnings of a gentle rain to the mortal remains of Megan Williams, put her head to a no-longer tormented brow, and wept bitter tears.