So something probably truly deserving of being in this thread.
Metagross. He's big. He's bulky. He's got a unique body. He's made of solid steel. And most importantly, he's a third generation Pokemon. And not only is he from the third generation, he's not a starter Pokemon. Metagross is THE ace card of Steven Stone (part time regional champion, and storyline quest guide). And I also feel Metagross is fairly popular among fans of Pokemon.
But that last sentence is the key. Popular among FANS. You know who else is wildly popular from the same generation? Gardevoir. And not only does Gardevoir insanely outpopularize Metagross from fans, even people who DON'T like Pokemon (but still excessively browse the internet) probably know what a Gardevoir is by now just from sex appeal. Blaziken, too. Who got into Pokken Tournament? Certainly not Metagross. Even god damned Grovyle gets asked for in Smash.
And it's such a shame, Crusade really has yet to have a heavyweight Pokemon on the roster. And even if a heavy were to be added, I'd pick Charizard over Metagross any day. Third gen seems to be in this strange limbo, but I still wouldn't want to just add the likes of Blaziken or Gardevoir because I don't feel like they would add anything really unique for the series.
I really liked Ivysaur. Not only was he the only four-legged fighter for Pokemon, but for the entire Smash roster to this day. Metagross in Crusade would be the best because of fighting on four legs, being a heavy in the Pokemon franchise, and just being a REALLY unique pick all-around. If Crusade were to give in to the "generation representation", Metagross would be my vote. But even I can't bring myself to make a thread for him, no matter the moveset I could think of. Even with the support of Oshawott, Chandelure, and Ampharos (two of them being pretty oddball picks in my opinion).