I'll gladly jump at any chance I can get to rant about this worthless pile of trash
Luvdisc in my opinion, is the objective worst Pokemon of all time in just about every category. Let's break it down, shall we?
Design: Let's start with the most obvious thing about it: the design. Now, given that Water is the most common Pokemon type, there's plenty of mediocre to even bad Water type designs, but I find Luvdisc's especially bad since it's so
bland. I know it's supposed to be a heart or a discus fish but honestly it just feels like the laziest, most hastily-thrown together execution of that concept. There's nothing visually interesting about it, it's not cool or cute or scary or nothing. It's just "there" in the worst way possible, and it's especially egregious in a region that's full of far more interestingly designed Water types (which you can find in the same places you can find this), and even moreso in the gens following it's inception
Typing: Getting a bit deeper, Luvdisc's typing only adds to the general blandness and badness that permeates this thing's design. Water, as I said, is the most common Pokemon typing, with there being 144 of Generation 8. To make matters worse, Luvdisc is a pure Water type, which makes up more than half of all Water types (with 10 others in Hoenn alone not counting Castform). So already Luvdisc fails to stand out on typing alone from all the other. However, this wouldn't be so egregious if Luvdisc had anything in terms of stats or abilities or even
moves to stand out from the others, but as we'll see, it doesn't, at least not in a good way
Stats- And this is where Luvdisc goes from just being another generic Water type to being complete and utter trash. Luvdisc's base stat total alone cements it as total garbage, coming out to a putrid
330 BST. That BST puts it on the same level as first form Pokemon like Zorua, Buizel, Finneon, Aron, and Voltorb, and
lower than the likes of Snover. That alone is bad enough, but once you get into the stats proper, it gets even worse. Outside of Speed, Luvdisc does not have a single stat over base 65, which for a single form Pokemon, is absolutely terrible. Remember, those other Pokemon I mentioned? They evolve, they get better stats, but Luvdisc will always be Luvdisc. Now Luvdisc
does have a base Speed stat of 97, which on paper doesn't seem terrible. After all, Water is a decent attacking type, so maybe with base 97 speed it could be a speedy attacker? Well no, because Luvdisc's attacking stats are abysmal, with base 30(!) Attack and base 40 Special Attack meaning that it isn't hitting
anything (for reference, unless it's both Modest and holding a Life Orb, Luvdisc cannot OHKO uninvested Garchomp from full with Ice Beam, a 4x super effective move). But since its attacking stats are so bad, you may think it's meant to be a faster tank or fast cleric or what have you, but it can't even do that well, not with 43/55/65 defenses it can't. So at least in terms of stats, it can't actually
do anything with that decent Speed stat. If Luvdisc's terribleness just stopped at stats, typing, and design, it would already be one of the worst, but the terribleness doesn't stop here. No, in fact, it only accelerates from this point onwards.
Abilities- On paper, Luvdisc's abilities don't seem
too terrible. After all, Hydration is a great ability on Pokemon like Manaphy, and Swift Swim is one of the best abilities in the game. However, when you remember its stat line, you realize why these abilities are absolutely terrible for it. See, the intention is that you would use Luvdisc on some sort of Rain team, abusing these two abilities to make it a threat under rain. But here's the issue: Luvdisc can't actually
utilize these abilities. After all, given Luvdisc's terrible bulk, why would anything bother trying to status it to activate Hydration when any decently strong move will 2HKO or just plain OHKO it? And while Swift Swim boosts its already strong speed, it doesn't have the offensive stats nor movepool to really take advantage of this, especially not when compared to fellow swift swimmers Mega Swampert, Kingdra, Seismitoad, and Ludicolo (introduced in the same gen no less), all of whom have better typings, better stats, and better moves to actually abuse this ability. And keep in mind, to use these abilities, Luvdisc
has to be in rain, so unless you're willing to give up a slot on a rain team for Luvdisc or build a rain team around it specifically, Luvdisc essentially has no abilities, and even when it can use them, it can't use them
well.
Moves- This is where it completely falls apart for poor Luvdisc, for even other comparatively terrible Pokemon like Delibird, Furret, Ledian, and Farfetch'd have decent
movepools (and better stats comparatively but I digress), but Luvdisc doesn't even get that. At most, Luvdisc gets the standard Water type fare, the same TMs most Pokemon know by default (like Toxic), and some relatively pointless options like Agility, Sweet Kiss, Heart Stamp and Heal Pulse. Even in the HOME leaks all it gets in terms of tutor moves is Scale Shot, which is worthless for it. So even in terms of moves, which can be the saving grace of many an otherwise mediocre or terrible Pokemon, Luvdisc gets absolutely nothing.
In-Game: So we've established by this point that Luvdisc has a generic type, bad stats, near worthless abilities, and a terrible movepool. This is already enough to make it worthless, but at least some of this would be forgivable if it was say, an early-game Pokemon. After all, many early-game Pokemon are generally bad by design, meant to be replaced as you go on or to at least get stronger as they evolve. But here's the thing: not only does Luvdisc not evolve, therefore robbing it of any chance to get better, but Luvdisc tends to be made available in the mid-late game. Why is this bad? Well, by the point you can get Luvdisc in most games, not only do you need something with Surf (usually another Water type) to get to Luvdisc to begin with, meaning that there's a good chance you already have something better than it by default, but by the time you can usually get it, there's far,
far better options.
The best examples of this are in Gens 3 and 4, where it is made available in the final city and in the postgame respectively. By the time you get to these points, you have access too and are likely using far,
far better Water types, and even if you aren't, there are plenty available in the places you can get it. For example, in Emerald, in the place you can fish to get it, you can also get Wailmer, Magikarp (at Gyarados levels), Pelipper, Tentacool, and even
Corsola , all of which are leagues better than it. And in DPP, you have to beat the Elite Four to get the Super Rod you need to get Luvdisc, by which point you should already have a good Water type, but even
then there's far better options in the places you can fish to get it.
So by these metrics alone, by the time you can get Luvdisc, there's no reason to ever use it since you should have better options available.
"BUT WAIT!" you may say, "Luvdisc isn't meant to be used in battle, it's meant to be used to farm Heart Scales!". Now first of all, if a Pokemon exists solely to shill an item, that's already bad, but this argument falls apart extremely quickly. The only place it could possibly apply is in RSE, but even then, before you can get Luvdisc, you can already grab up to
14 Heart Scales, which is more than enough for a casual playthrough. But even if you need more if say, you want to play competitively, you don't even need to
catch Luvdisc to do it, since you can just give something Thief and have them steal Heart Scales. So the one thing Luvdisc
could be used for doesn't even need you to actually
use it.
But like I said, it only applies to RSE for in every Pokemon game after where Luvdisc is available, there are
also sources of infinite or at the very least near-infinite Heart Scales, whether those be respawning locations on beaches, Festival Plaza floats, daily events, the Underground or other such things, you can easily get Heart Scales without even
seeing this garbage excuse for a Pokemon.
Oh, and it isn't available in SwSh because even GF in their incompetence knows that this mon is worthless but even if it did come back, the move relearner is now free so there'd literally be no point in using it. So yeah, Luvdisc is objectively worthless in-game. Hell, even as an HM slave it's worthless since by the time you can get it, you already have access to/are using other HM slaves.
Competitive: Finally, we end on Luvdisc's competitive value or well, lackthereof. Let me put it this way: I have searched through every viability rankings for every tier in every generation, even down to sub-ZU tiers on other forums. I have seen every other garbage Pokemon from Delibird to Ledian to Furret to even Unown ranked and shown to have
some level of viability somewhere, no matter how small. But Luvdisc? Luvdisc is not on any viability ranking in any tier in any generation. It's so unviable it has never even been touched in the lowest of low tiers like ADV ZU, where Pokemon like Elekid and Delibird rain supreme. It's completely worthless
So in conclusion, Luvdisc is demonstrably, objectively, the worst Pokemon of all time. It has garbage stats, a garbage design, garbage moves, worthless abilties, is useless both in game and competitively, and has the most generic typing of all time. Every other Pokemon has at least something, anything to make it redeemable, but Luvdisc has literally nothing to its name. It is truly the bottom of the Pokemon barrel, the creme de la creme of garbage.
To everyone who had the patience to read through all of this, thank you.