(there's some exposition of my worldbuilding in the author's notes, so if you usually skip those, I'd advise you read this one)
After an amazingly long and boring trek along my dirt path, one filled with arduous toil and grand endeavor, (it totally lasted longer than five minutes, I don’t know what you’re talking about) I reached Some Sort of Cave.
I say “Some Sort of Cave” because it was actually a giant cardboard box with the words “This is Some Sort of Cave” scribbled on the side.
There go my detective skills again, showing off their awesomeness to the world.
“Knock, knock,” I called as I entered. After all, it’s rude to enter without knocking, even if it is a cardboard cave.
To my surprise, somepony called out, “Who’s there?” from inside the cave.
Guess there’s a box-dweller with some modicum of common courtesy living ‘round these parts. Either that or some seriously messed up echo.
...
My bits are on the echo.
"I don't know!" I replied.
"I don't know who?"
Its voice sounds about right for an echo.
"No seriously, I don't know. Who am I again? Oh right, some sort of zombie pony on a mission of utmost importance," am I rambling? I think I'm rambling. I should probably apologize or something. "Sorry about the rambling! Can I come in?"
"Sure thing, confused stranger!" the echo called, "My cave is always open to you potentially dangerous zombie-folk. Come right on in."
The inside of the box was rather shocking. Instead of corrugated cardboard-ey goodness I expected, I was met with the cold stone and awesome stalagmites/stalactites of a limestone cave. It was also smaller on the inside.
"Nice place you got here," I commented as I admired the sights.
"Thanks," the echo replied from somewhere behind me, "I try to keep it looking spiffy for any visitors I get."
I nodded, echos are known for being good hosts. Makes sense since echos are actually magical spirits which feed off of noise, and happy ponies are more likely to talk longer. "Well you've certainly done a good job but, if I may ask, what's with the cardboard exterior?" I turned around to face the echo, but didn't see anything there.
"Cardboard...?" the echo asked, still from behind me, sounding confused.
"Yeah, you know how the outside of your cave looks like a great big cardboard box?" I clarified, spinning in circles. Maybe if I spun fast enough the echo would get dizzy and slow down?
"Oh!" The voice of the echo, which always came from behind no matter how fast I spun, now sounded concerned. Should I be concerned too? "That's actually an illusory advertising mechanism. It's supposed to read the viewer's mind and show them a pleasing exterior to lead them down here, but I think it might be broken. Really more of a gimmick, if you ask me."
"Why would an echo like yourself need help bringing ponies to your cave?" I wondered. Ponies usually flock to echo-ey places for fun. The echo entertains them and the ponies feed the echo. It's a win-win situation.
My host stifled a laugh. "Wait," it sniggered, "you thought I was an echo?"
"Yeah, what else would live in a cardboard box out in the middle of nowhere?"
Seriously, that's prime echo real estate there.
The not-an-echo couldn't contain its laughter any more. "Oh, that's just too rich!" I heard the sound of a knee being slapped behind me. "I'm not an echo, my little pony." my host finally stepped in front of me so I could see him. "I'm a mirage."
And indeed he was a mirage, complete with the indistinct outline and indiscernible features they're known for. That explains how he could stay behind me and how he could put up that awesome illusion outside. Mirages feed on confusion and false hope.
"Well it's a pleasure to properly meet you, Mr mirage. Do you have a name?" I asked, sticking a hoof out.
The mirage's form pulsed as he talked, sort of like a sub-woofer or something like that. It was kinda cool to be honest. Not as cool as me, of course, but still cool.
He grasped my hoof firmly with his amorphous appendage. "Nice to meet you too, little pony. My name's Fphantom."
"Phantom?" I asked, "like a ghost?"
"No, Fphantom," he seemed irritated, as if he'd explained this same thing countless times before and didn't like doing it, "with both an 'F' and a 'ph'. Fphantom."
"Alright Fphantom. Hey, do you mind if I call you 'Fphant'? Fphantom's kinda long." Fphant shook his head no. Wait, "Is that a 'no you don't mind' or a 'no you can't call me that'?"
"It's a 'no I don't mind'" he clarified with a roll of his eyes.
"Alright Fphant, you seem like an open-minded fellow," I grinned like the madpony I was. "How would you like to join me on an adventure?"
His interest seemed piqued, that's good. "What kind of adventure?"
"The best kind of adventure!" I told him, my madpony grin growing even wider. "The kind filled with awesomeness and radicalness! Traps and tricks! Muffins and cupcakes!" I struck an awesome pose. "We're gonna go finish up what I started in the last life! Overcome all odds! Win the day, save the girl, and all that jazz!"
I could tell Fphant was all for it, hell, a foal could tell he's all for it! He looks so ready to go he's shaking! Oh wait, that's just me. Whatever, he still looked like he was all for it. I think. It was slightly hard to tell since his face kept changing shape.
"Are you ready to go Fphant?" His response was a frantic nod. Or maybe it was a normal nod and a shrug which seemed to say he's got nothing better to do. It's so hard to tell once I stop caring but if that's not a "yes" then I'm sane! "Off we go then! Into the wild blue yonder, destination: Thataway!"