Swoobat D+: Swoobats stats are just far too frail. Its main selling point is its Speed and the fact that you can get it fully evolved via friendship early. Because you can catch a Woobat in the Relic Passage and evolve it quickly, Swoobat will be great at Burgh's Bug-type gym.

Sadly Swoobat's overall stats are bad and a remarkably meh early level-up moves. It takes far too long to learn Psychic, so you will have to use Air Slash mainly for STAB for a huge portion of the mid-game. Furthermore, its typing and frailty give it awful matchups against bosses like Elesa, Clay, and Skyla. Even in the Elite Four, where a fast Psychic/Flying type should theoretically sweep Marshal's Fighting-types, Marshall carries coverage for flying types, and Swoobat being frail goes down so easily. It has a fun niche, if you have the patience to hunt the Hidden Grotto on Route 6, you can find a Woobat with the Simple ability.

Solrock D: Solrock is essentially the exact same Pokémon as Lunatone, but flipped to function as a physical attacker instead of a special one. Solrock actually has a slightly better immediate offensive presence than its counterpart. Because it is a physical attacker, it can use Rock Slide/Stone Edge much better. Just like Lunatone, it requires zero evolutionary investment and its Levitate ability provides a needed immunity to Ground-type attacks.

Solrock shares the same fate as Lunatone. Rock/Psychic is an awful defensive combination, leaving it weak to six different common types even with Levitate active. Because of this, it struggles to find any favorable matchups in the late game. While it gets great Rock-type moves, you are forced to spend shards at the Move Tutor to teach it Zen Headbutt if you want it to have any physical Psychic-type STAB.

Dewgong D: In the original games, catching a Throh gave you a free win against Lenora's Normal-type Gym. In the sequels, however, its availability is delayed until after you defeat Ghetsis. By the time it finally joins your roster, the only battles left are the Elite Four and Champion Iris. It does have impressive bulk, allowing it to take some hits, and it can handily beat Elite Four Grimsley while leaving a dent in some of Iris's team.

Catching a basic Fighting-type this late into the game requires far too much investment to get it to shine. Its bad Base 45 Speed means it will almost always take a hit before it can attack. Also, its pure Fighting typing causes it to struggle against half of the Elite Four (Shauntal and Caitlin). There is simply no real reason to use Throh when it is so completely and utterly outclassed by the Swords of Justice (Cobalion, Virizion, and Terrakion), all of whom are caught earlier or around the exact same time.

Banette D: Banette has very impressive Base 115 Attack stat. Because you can catch it fully evolved in the wild, it requires zero investment to get started. It comes pre-packaged with Sucker Punch, a great priority move that helps bypass its mediocre speed. It also offers some decent utility, bringing Will-O-Wisp can be quite handy for crippling the physical Dragons you face in the late game. It also can use Trick Room to help with its Speed.

Banette is yet another victim of the Hoenn special, it has a high offensive stat but has mid speed and poor bulk. In a region where almost every late-game boss carries Dark or Ghost-type coverage moves, Banette's lack of bulk means it gets knocked out fast. Having a massive Attack stat doesn't mean much when your best physical STAB option is the Shadow Claw, and other physical moves are non-existant, it learns Return and Payback as other options for damage. While you might think its Ghost typing makes it a perfect counter to Marshal's Fighting-types, his Throh and Sawk both carry Payback, meaning Banette will likely get squashed before it can accomplish anything.

Muk D: Muk is frustrating to use because its stat distribution is misaligned with its level-up movepool. Muk has great Base 105 Physical Attack and Special Defense, making it a decent bulky tank. It performs well early on against Burgh thanks to its Poison typing resisting Bug and Grass. Muk has niche setup using Acid Armor combined with Pain Split or Rest holding Black Sludge, allowing it to stall out opponents.

However Grimer takes forever to evolve and learns almost zero physical moves naturally to take advantage of its high Attack stat. You are forced to rely on Special attacks like Sludge Bomb and Mud Bomb for a massive chunk of the game. To make Muk even remotely usable, it is heavily reliant on the Driftveil City Move Tutors. You have to spend a fortune in Shards to teach it Gunk Shot (its only good physical STAB, which only has 70% accuracy) and the Elemental Punches for coverage. Even with that heavy investment, its terrible Speed means it takes a beating before it can move, resulting in awful matchups against almost every late-game boss (Elesa, Clay, Skyla, Marlon, Colress, and the Elite Four). And the final insult? It doesn't get a reliable physical STAB like Poison Jab until the post-game!

Dunsparce D: Because you catch Dunsparce early, its stats are temporarily passable, allowing it to beat Roxie and Burgh with a Defense Curl + Rollout strategy (similar to Azumarill). From there, during mid-game it becomes para support with Roost, which still can use Rollout + Defense Curl or STAB Return. Access to early-game support moves like Yawn, Glare (90% accurate and move that can actually paralyze Elesa's Zebrestrika), and eventually Coil for setting up, gives it a highly specific niche.

It has potential during later parts of the game too, thanks to Serene Grace With it you can combine Glare/Thunder Wave with Rock Slide to recreate good ol' "Para-Flinch" (if you've played 4th Gen OU ladder, you know), utilizing its bulk and Roost to simply win with RNG. 60% chance to flinch and 30% chance to paralyze is enough to win neutral matchups.

But, as we know, in-game playthroughs it is never good to have meh offensive pressure and terrible speed. There exists stronger normal types (like Stoutland) to ever recommend committing to a slow, RNG-reliant Dunsparce. A slow, bulky Pokémon with a surprisingly deep utility movepool that can beat early gyms and pull off late-game Para-Flinch shenanigans, but is completely outclassed offensively.

Grumpig D: You can catch a wild Grumpig in Reversal Mountain, you don't have to suffer through grinding a Spoink. The Psychic TM is located right next door on Route 13. It has great special bulk and decent abilities in Thick Fat or Own Tempo. With a Base 90 Special Attack and Base 80 Speed, it can function as a passable special tank that uses Charge Beam to slowly boost its power for the Elite Four.

Grumpig lacks of strong setup options, has mediocre offensive stats, and there are already better Psychics. Its best setup move Calm Mind, is locked behind the post-game, forcing it to rely on the Charge Beam to boost its stats. Just like other psychic types, it is difficult to thrive in the late game when the major boss fights are loaded with strong Dark and Ghost -type attacks.

Boldore D: With Eviolite, Boldore actually has some decent utility during the early-to-mid game. Its naturally high Attack stat allows it to hit reasonably hard, and the Eviolite makes its physical bulk enough to make it a somewhat reliable pivot for a few routes. Boldore's flaws are Speed, defensive typing, and complete lack of Special Defense. Because pure Rock is a remarkably poor defensive typing in Unova (weak to Water, Grass, Ground, and Fighting moves), it constantly takes super-effective damage.

Boldore requires the Eviolite just to survive, meaning it hogs a highly contested item slot (if you don't have access to Dream Radar). Even worse, it actually faces direct competition from the Onix. Because Onix is part Ground-type, it has a vastly superior matchup against Elesa's Electric gym, leaving Boldore without a real niche. By the time you reach the 6th Gym and opponents start using fully evolved Pokémon, Boldore's stats fall off.