*** Art by  Virmir! ***

"I wanna ride the Ferris wheel!"
Roger held Alicia's cotton-candy-stained hand while she skipped along the boardwalk beside him, marveling at everything. They came to one of those rigged games, and the girl skidded to a stop and said, "Let's try this one first!"
Roger knew the ball-throwing game was unfair, but couldn't say no. She played and couldn't topple any of the acorn-shaped targets. But then she tried again and by sheer luck, knocked one loose.
The guy in the booth was about to hand her a junky plush bear, but just then a woman clad in odd starry robes burst in from the side. "Wait. This girl needs a special prize."
"Huh?" said the startled teenage carny.
The lady fished out a plush acorn made of shimmering cloth and held it up, speaking with reverence. "Only one with the power of love can wield such a mighty artifact!"
Alicia giggled and hopped to try to snag the prize. But she banged into the counter and fell. Her cry of pain made Roger dive to catch her, to keep her from hitting her head on the wooden floor. She landed in his arms, sniffling but okay.
The little toy had fallen from the startled woman's hands to the counter. Roger snagged it to pass it to Alicia, saying, "You won, but be careful now."
Before she could take it from his hands, something yanked Roger to his feet. He yelped and found himself floating, with the toy spinning around him and emitting sparkles. "What? How?"
The robed lady said, "No, that was supposed to be for her! But... it's working anyway?"
"Get me down from here!" Roger said, but the words slurred because something was happening to his teeth, seeming to pull them forward. His ears poked up taller to catch the sound of a cheerful tune coming from nowhere.
Alicia stared at him. "Dad, you've got a tail!"
Roger tried to turn and look, but in midair the movement spun him all the way around and gave him a look at a long, fuzzy grey brush extending from his spine. "Step away, Alicia; I don't know what's happening!"
The carnival woman was flustered now, looking back and forth between wide-eyed Alicia and hovering Roger. "Oh dear. But it seems you're qualified too."
That wasn't the end of the changes, of course, and it was only the beginning of...
Magical World-Climber Oak and the Vanir Legend!

(Got this sketch a while ago and had this vague idea lying around. So here's a quick version of it! Reminds me of "Princess Holy Aura", which shows how troublesome a situation like this would be.)