So I was thinking of what are some hypothetical mods for PLA that you could get a variety of gameplay with as few assets and code required.
But I think I daydreamed up a challenge that might have some interesting gameplay and metas, but I'm just spit balling here.

It's P̶it-No, Tower of 100 trials except you can only use pokemon lvled up to the "highest" floor you are on.
So on Level 10 you can only use lvl >10 pokemon, floor 25 lvl >25 pokemon, floor 69 lvl >69, etc.
[You start at floor 10 where you must ascend up to floor 100 to face the Terrible Ten]
Each floor spawns a random pokemon that's level is the current floor #. [with move pool adjusted accordingly]

you must choose which 6 pokemon and at what levels they are at.
By default you must have a "starter" at lvl 10 (just going from the previous rules)
but all the other mon's you have you will need to a have good spread across lvls 10-100 if you want to reach the top!
There is exp gain so your party will level up somewhat so do keep that in mind.

You get 6 revives, 6 max heals, and 6 PP restore items
[there are Pokecenters to heal on floors 25, 50, 75, and 100 before you fight the Terrible Ten]
[You also get +1 extra retry on these select floors as well, you restart at the last Pokecenter you were at,floors are rerolled]

For Game Balance reasons and to give an appropriate finale, the Terrible Ten should be predetermined. They should be really hard but not dumb insane impossible hard, that you can only win by abusing the battle system.