Mechanically, what would you think of a Dark-type Pokemon that functions like an “anti-Zoroark?” What I mean is: imagine a Pokemon that has high stats on average, but no/few moves it can learn or be taught/bred on its own. Instead, it has a unique ability that works like the move version of Zoroark’s Illusion, where it fills in any empty move slots it has with the moves from those slots on the last Pokemon in your party? This is why I’m calling it an “anti-Zoroark”—while with Zoroark it always has Zoroark moves but hides under the illusion of another Pokemon, with this “anti-Zoroark,” you always know the type of Pokemon it is, but it could come at you with almost any move, based on what’s in the party with it, and generally has the stats to make them work? Weirdly enough, it’s a Pokemon where forgetting moves is actually *encouraged* (more empty move slots to fill with its ability). I get that this is a super gimmicky idea to base a Pokemon around, but is it an *interesting* gimmick, or just dumb?
Without more details, my first instinct is that this is too strong – like, if it has good stats and a bad movepool, but its bad movepool doesn’t matter because it can have practically any moveset you want, then that seems extremely good to a degree that is probably dangerous. The fact that its type coverage is going to be redundant with something else on your team is a limiting factor, but it could also have other tricky bull$#!t that just doesn’t rely on fighting toe-to-toe; maybe it has Spore or something, which on a fast Pokémon has a lot of potential for abuse. Hell, maybe you just put Smeargle in your last slot; then “anti-Zoroark” can have literally anything you want, but on a body with actually good stats. That’s terrifying. Of course, you can’t ever make a Pokémon forget its last move, so this thing is always going to be stuck with one move of its own. If its natural movepool is really $#!t – like if there is nothing good in there whatsoever, not even a good Dark-type STAB move – you could design a Pokémon that effectively has only three moveslots, which might be interesting. Without actually diving into all the zillions of possible combinations of moves out there, or doing the calculus of whether this is good enough to be worth having a Smeargle on your team with a moveset designed for a high-statted Dark-type, I really don’t know where this falls from a balance standpoint. And, of course, in the post-Sword and Shield era, maybe you can just never allow this thing to exist in the same game as Smeargle; that’s probably safest. Still, my instinct is very much to assume this thing will be super overpowered unless someone can really convincingly prove otherwise.