The thing with Zelda / Puff / every other perceived "bottom-tier" is, somebody has to be on the bottom. It doesn't matter how good, bad or indifferent they are, unless you balance the game to be absolutely equal in every possible context, there will have to be somebody that's perceived as weaker than everybody else. Even PM, a game with relatively strong 1v1 balance, has its bottom-tiers. They might be damn good bottom-tiers relative to every other Smash's roster, and probably more than capable of holding their own with most of the roster in, say, Brawl, but they're still the weakest character(s) in the game and therefore must be the worst.
People need to stop treating bottom-tier as some kind of inescapable prison of absolute non-viability or a terrible curse that brings only shame and ignominy. It's inevitable, somebody has to be down there, even if it's just because they're not as objectively good as everybody else. If that character happens to be your main, then that's just the fall of the dice. Trying to demonstrate why your main is better than perceived is fine, but trying to convince others that "this character is mid-tier, you just don't get their true potential" does nothing. It's a platitude. It does not yield productive discussion. If your character is the worst, it doesn't make them objectively bad or fundamentally unserviceable, it just means they're not of the same distinction as other, higher-tier characters.
If you really want to prove your character is good, don't vent your frustrations typing this in-depth theoretical treatise on an internet forum, go out and do something with them. If you really believe in what you say and you're willing to defend your beliefs in front of the whole world, then pick up that controller, get to training and make something of the character. Hungrybox made people take Jigglypuff seriously in Melee. Nairo demonstrated that Doc, in the hands of a skilled player, has viable opportunities. You probably won't be either of these players, at least not immediately, but you might make waves in your immediate scene or beyond. It's a damn sight more productive than citing theory and results that don't mean anything to anyone, trust me.