I feel like the Pokémon games' assessment of what would happen if the world were overrun by giant super-powered creatures is a little... optimistic.
DeviantArt user Arvalis—of Pokemon-as-giant-friggin'-dinosaurs fame—has taken to pointing a Monster-Hunter-fication beam at some of his favorite no-longer-pocket-sized monsters. The result? Creations like this awesome Charizard, a beast of majesty, harrowing size, and probably a lot of good crafting materials. If this hypothetical monster mash-up actually existed, you'd slay him, of course. It's nothing personal in Monster Hunter. Just part of the job.
Inspired by this, Sketchfab user Zaphiron took things one step further, giving a number of Arvalis' Pocket Monster Hunter creations the full 3D modeling treatment. The end result is quite a sight. I think the last, withering embers of my childhood would die if I cleaved a Nidoking clean in two with a sword twice the size of an armored man two times larger than me, but I'm not saying I wouldn't if given the opportunity.
Next up, Flygon:
Here's Tyrantrum, perhaps the most Monster-Hunter-y looking of them all:
And finally, here's good ol' Nidoking, aka Barney the Rhinosaur:
You can check out all of Arvalis' originals (and tons more) here.
So there's some imagination fodder for you. I'd say the notion of a Pokémon Monster Hunter game is far-fetched, but well, Zelda recently got a Dynasty Warriors spin-off, so we live in a world where anything is possible.