Every time I have played the modern Pokemon games I’ve done the same thing for my party so I guess it’s what my gym would be too:

Basically the whole thing is like the imagination room from OG Willy Wonka, everything is food and edible, with my pokemon being all the food themed ones. The apple pie dragon, the ice cream cone line, bread dog, etc (I’m sorry I always rename my pokemon as soon as I catch them so have no idea their actual names anymore)

Magikarp.

A gym filled with thousands of gym trainers, before you reach the gym leader. Each with 6 high level magikarps with as much hp up and defence supplements that they can take.

The sheer scale of the amount of Magikarps you need to face will make it an immense undertaking.

At the end you get a TM for Splash.

It’s just Snorlax, Slowpokes, and Slaking. We’re just hanging out watching old movies

We don’t even have to fight, if you bring snacks I’ll give you a badge

Ice type gym. However, the floor’s ice, and if you walk around with a Fire type behind you/use too many fire moves on the trainers before me, it cracks, and you go under the ice—to a mirror version of the gym, but with water types! Remember, don’t overcomplicate. This is for six-year olds. A bit complex, but not worse than the Seafoam Islands. And yes, I’d have an Articuno (at least, if I were one of the Elite 4-equivalent rematchers, maybe a Legendary Pokémon would be unfair for a gym).

My gym would start with a trainer having the latest generation Pokemon, then each one after would have ones from the previous generation.

Once you’ve gone through all generations and get to me, my team would be one high level Pokemon spamming its strongest move, and any time it got to red health I’d swap to a level 10 Pokemon that only knew HMs while I full restored my high level one.

I want a gym that is entirely done in beige and warm greys, with a slight buzzing from AC and florescent lights.

All my Pokemon will be normal type

I don’t have a real answer but I just wanna say this question and your answer are awesome, I can’t wait to see some more answers!

My gym would be the cutest cuddliest Pokemon leveled to high hell, with some level ones mixed in. Then Id give people guilt trips for bullying the weak ones.

No type theming. The common thread is turtles. Squirtle line, Turtwig line, Shuckle, Torkoal, and I’m pretty sure there are more since Emerald that I don’t know the names of.

Under water gym. No, not water like Misty. Under water.

I haven’t figured out all the logistics. How will people breathe?

Seaweed mazes and cool cave grottos, sunlight filtering in from above,

There’s rocks and plants and corals and shit under water. My trainers will use all those Pokemon. Not sure about ice yet. That can be in the sequel game – the icy under water gym.

Dark type. A bunch of tall goth chicks on the path to me.

All food based Pokémon. I think that was a gym though? Lady with a cafe though, had a fidough maybe? Me and my Pokémon would be just trying to have a garden, give out food to travelers. We’d all be objecting to being a gym leader lol.

I always wanted to have a full team of glitch Pokemon:

Ash is wading along the beach on cinnabar island when suddenly he falls over onto the hard ground. Bright light comes from all around as he looks up in shock to see a strange emtpy wireframe space.

As he gets up, a piercing noise shatters the silence, it seems to come from inside his own head. A shadowy, pulsating form fades and crackles into view. An ‘arm’ extends and throws a ball, completely black like a void. Exploding from within is a pokemon…? No It can’t be! Ash stares wild eyed at the strange rectangular form, a chunk missing in its top right corner. It shrieks as it ripples with strange patches of incomprehensible randomness.

Ash’s vision flashes for a moment back to the beach, he’s staring up at his friends as he lies on the sand. They’re saying something but he can’t hear it. He can’t speak, his eyes are portholes and he’s trapped inside. Then he’s gone, back to the broken liminal space.

The pokemon is approaching. Or is it? It doesn’t seem to exist properly, a 2D form in a 3D space that only seems to grow in his vision. Ash looks down to see pikachu by his side, hair standing on end. They exchange a glance and he knows what to do.

The fight is a blur, each new opponent more incomprehensible and impossible than the last. As the final entity is destroyed. Ash falls to his knees, his mind shattered by the infinite cosmic chaos. The strange ‘gym leader’ begins to fade and the world starts to crumble to blackness. A bright light is shining. A voice emanates from all around. “Wake up ash you’ll be late for school.”

Ash opens his eyes and looks around, he is in bed. The world seems so much more detailed, so much more real. A handheld gaming device rests on his chest, white light flashes from its LCD screen as a pixelated title cutscene plays. A single word appears. PoKéMoN™

bed

I’m not sure what pokemon I’d be using (probably dark/psychic) but I know I’d want the gym itself to have an optical illusion theme. It would have a lot of fake walls and floors, floors that look like bottomless pits, and all of it would be encompassed in a series of rooms designed to make you feel like your walking through a maze like MC Escher painting.