There are many powerful Pocket Monsters in Pokémon Legends: Arceus, but there are also some weaker ones that deserve to be buffed. In the games, many Pokémon undergo evolutions when certain conditions are met, such as a level, specific move, or item requirement have been met. Usually, Pokémon that evolve will gain a substantial increase in their overall stats, further enhancing their battling capabilities. Despite the drastic change in both appearance and power, there are some Pokémon that remain far too weak to be viable beyond certain points in the game.
Although many Pokémon can evolve in Legends: Arceus, some of the weaker options that need a buff are also the Pocket Monsters that can't evolve. Characters like all of the Unown in Pokémon Legends: Arceus serve a greater purpose in the game, despite being unable to evolve, so in this particular instance it's okay if they remain in a single form. Others, however, are too weak to be used on their own and certainly deserve to be buffed.
First and foremost, Raichu deserves to be buffed. Even if the Pokémon isn't originally from the Sinnoh region, Raichu has suffered because its pre-evolved form is the mascot for the franchise at large. No other Pokémon in-game, across multiple titles, has received as much attention as Pikachu. The Pokémon even has a unique item in other games that it can hold called the Light Ball which doubles both Pikachu's Attack and Special Attack stat, allowing it to outperform Raichu in both stats. Raichu, at the very least, deserves to have a similar stat total to that of Jolteon and the rest of the Eevee evolutions in Pokémon Legends: Arceus.
Carnivine, Pachirisu, & Chatot Deserve To Be Buffed In Legends: Arceus
Excluding the Unown and Legendaries, the only three Pokémon in Legends: Arceus that do not have any evolved forms are Carninvine, Pachirisu, and Chatot. As a result, all three are embarrassingly weak options to use in-game beyond certain points, unless players overtrain them by an extra 10 levels at the very least. Even then, there are far better options than Carnivine, Pachirisu, and Chatot simply because their movepools and strengths are weaker than similar Pokémon like Leafeon, Jolteon, and Staraptor, respectively.
Carnivine, at least, is a little more useful with a total stat base of 454, especially considering its worse stat is its Speed. Pachirisu and Chatot, however, both have total stats at 405 and 411, respectively, and they each deserve an evolution to receive further increases in power. Carnivine should receive either an evolved form or overall buff to its stats, but nothing identical to what Tangrowth or Leafeon have in Pokémon Legends: Arceus.
Bug-Type Pokémon Need A Major Buff In Legends: Arceus
Throughout many games in the Pokémon franchise, Bug-type Pokémon have always been a means for players to get from point-a to point-b while introducing one of the games' core mechanics. Bug-type Pokémon typically evolve early, seeing substantial increases in their stats when compared to other Pokémon in the area. However, too many Bug-type Pokémon have too many weaknesses, whether it be from 2x or 4x super effective moves that result in them losing fights after receiving a single attack from almost any opponent. Not every Bug-type Pokémon needs a buff, however, just the ones that are severely underpowered. Both Beautifly and Dustox are perfect examples of Bug-type Pokémon that need a buff, but Scyther and Scizor in Pokémon Legends: Arceus are examples of Bug-types that are perfectly fine with their current stats.
Other Bug-type Pokémon that deserve a buff in Legends: Arceus are Parasect, Mothim, Wormadam, and Kricketune because their overall stats are absurdly low for final evolved forms. Kricketune falls into the same category as both Beautifly and Dustox, having evolved from its previous form at a low level without gaining a substantial increase in power. Parasect, Mothim, and Wormadam, however, all evolve from terribly weak Pokémon without receiving much of a strength boost as well. Other than to complete the Pokédex in Legends: Arceus, there is little reason to use any of these options. Even though Bug-type moves deal 2x damage to both Psychic- and Dark-type Pokémon, these particular options have low enough stats to the point where the type advantage doesn't particularly matter against final evolved forms like Weavile or Alakazam in Pokémon Legends: Arceus.
Lastly, given that the Hisui region is mostly unsettled by humans, Bug-type Pokémon deserve a buff in Legends: Arceus because they are in an environment that best suits their strengths. The Hisui region is teeming with untapped resources for Bug-type Pokémon to grow stronger, and their sheer numbers and physical size should have allowed them to more easily dominate predators. Even in the wild, they still evolve faster than their biggest threats, which should have made them the apex predator in a couple of the explorable areas of the map.
Legends: Arceus' Fossil Pokémon Deserve A Buff
Although the fossil Pokémon in Legends: Arceus aren't particularly weak, they definitely deserve a buff because they aren't revived directly from fossils like they are in other games. Through Space-Time Distortions in Pokémon Legends: Arceus, specifically those at Mt Coronet, players can find the four fossil Pokémon of the Hisui region, namely Cranidos, Rampardos, Shieldon, and Bastiodon. The reason why these Pokémon, or at the very least Rampardos and Bastiodon, deserve to be buffed isn't that they have low stats, but rather because of Mega Aerodactyl.
In the Pokémon world, the power of Mega Evolution allows some of Aerodactyl's dormant genes to reawaken. Some researchers believe that Mega Aerodactly's appearance is actually what the Pokémon looked like before it was fossilized. Through the use of revitalization technology and an Old Amber, scientists were able to extract DNA and bring Aerodactyl back to life in a less fearsome form that was almost undoubtedly not the original Pokémon. Had Bastiodon and Rampardos in Pokémon Legends: Arceus appeared with altered and more powerful forms, the theory that Aerodactyl's true form was its Mega Evolution could have been better supported. Granted, Aerodactyl does not evolve from another Pokémon as Rampardos and Bastiodon do, but that's all the more reason for buffing their pre-evolved forms as well.
Alternatively, because both Rampardos and Bastidon have a total base stat of 495, both Pokémon could have received evolutions that brought them up to pseudo-legendary status. Either a buff or a new form for each fossil Pokémon would have fit in perfectly with the game's additional retconned evolutions, bringing them to a stat total that rivals even Alpha Garchomp in Pokémon Legends: Arceus.