Leo's duel was well underway, against a boy who'd only called himself Coachman, broader than he was tall. Luna cheered him on. The boy had issued the challenge and Leo had accepted, despite his warnings of taking it seriously even for a casual challenge.

Leo, however, hadn't. He'd been trying to show off and play around, and Coachman grew bored as he readied a new Duel Monster, what seemed to be a silver donkey.

"...Candlewick's Mirror? Never heard of that before," Leo said.

"It's one you should take seriously. It has strong consequences from underestimating it."

Leo did not heed this warning, and was stunned when his efforts to attack saw the silver donkey barely harmed, and instead glow.

"It seems you're not listening. Let's raise the stakes," Coachman said.

Candlewick's Mirror then shone brightly, bathing Leo and Luna in the light. The twins winced, Luna rubbing her eyes.

"What was that?" She asked, and then felt her ears itch.

She reached up to one, and gasped, for it was growing longer, and furry.

Leo watched in shock as his sister sprouted donkey ears covered in grey fur, and then she cried out in surprise as she fell to all fours, her body shifting and twisting. Before the shocked eyes of her brother, grey fur began sprouting, seemingly absorbing her clothing as it grew.

"Leo! Help mee--haw!" She cried, her nose starting to elongate into a donkey snout. 

Stunned into silence, he stared as her hands began to shift into hooves, her feet doing the same. The fur was growing thicker and thicker, almost all that showed her as human gone, bar her eyes, her hair, and her terrified expression, her brays and honks efforts to beg her twin for help even as he stood transfixed in surprise and fear.

And then finally, out sprouted a donkey's tail, and the panicking girl turned donkey brayed in sadness and dismay, staring towards her brother with watery green eyes below the two high ponytails and bangs now resting above an equine neck.

"...Luna?" He managed to say, the grey furred donkey looking down mournfully.

"Now perhaps you might take this seriously. Defeat Candlewick's Mirror to turn her back. Fail, and you may well join her..." Coachman warned.

Tearing his vision away from his transmogrified sister, Leo fumed, and got serious....