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.

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).

I like water types, and there are a few dual type mons that bring in some type advantages to counter what one would typically bring to a water-type gym (e.g. Palpitoad/Seismitoad and Marshtomp/Swampert are all water/ground to nullify electric types, or the Lotad line to avoid grass-type weaknesses).

As for a gym theme, I like the idea of a spa/thermal baths place that functions as the town’s Pokémon Center, with a closed off area for gym challengers. Gym leaders are often important members of the community, so I think it makes sense that the gym leader would have other duties to their town in addition to battling.

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

Is sloth a theme?

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.

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.

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.

Dual types with no duplicates, so no type is ever shared by two pokemon, the gyms theme is the strength of diversity.

Mine would be an unassuming mostly empty room with a table and comfy chair in the center and instructions to put on a VR headset.

You do and the headset activates to reveal it’s a Rotom that transports you into a fantasy realm where your Pokémon team is reduced to level one and you have to fight your way through a gauntlet of wild Pokémon and trainers to quickly level them up until you reach me at the end, the electro gaming master.

If you lose, you are booted out and have to start over from the beginning, but the currency you earned remains that you can use to unlock permanent bonuses your next attempt. A ghost of you will also spawn where you fell last time and challenge you to a fight. Are you strong enough to conquer yourself and the gym?

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.

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