Legendary Pokémon are regarded as the strongest and rarest Pokémon in the entire franchise. Each game only holds one of each kind to capture, so make sure you have the right Pokemon and equipment with you before a long encounter. While they’re often captured to enhance a collection, legendary Pokémon are also used for battles. Many times, their superior stats, movesets, and abilities push them through the ranks, making them some of the strongest creatures in the entire franchise.

Take one look at the competitive scene, and you’ll see that certain legendary Pokémon are considered serious threats. Many players even add moves or Pokémon to their teams specifically to counter some of these legendary Pokemon. Many of these rare beasts live up to their name, which is just one of the many reasons why people want to have them so badly.

However, not all legendary Pokémon are created equally. For every that dominates tier lists and appears a lot in actual events, there is another that has poor stats and will never make it to the big leagues. These legendary Pokémon are the definition of underwhelming and are often less viable than random Pokemon one could find in tall grass. They’re only for collectors and no one else.

The Pokémon series is constantly evolving with new legendary Pokémon to capture. If you’re thinking about getting into the competitive side of the series, you may want to consider the most powerful legendary Pokémon and 15 that are too weak to make a difference.

POWERFUL: MEWTWO

Canonically one of the strongest Pokémon in existence, it makes sense that Mewtwo would also be one of the most viable Pokémon in the games. Its stats allow for it to throw out a lot of damage, its move pool lets it cover a lot of types, and its two Mega Evolutions give it the versatility that it didn't need in the first place. Game Freak set out to create the world's strongest Pokémon and they definitely succeeded with Mewtwo.

WEAK: PHIONE

Phione is often a legendary Pokémon that people forget about. That's partially because it's kind of a baby version of Manaphy, but it's also because its stats leave a lot to be desired. Manaphy is better in every way, being a Pokémon that has a lot more potential. It has the same number for each of its stats, but that number is so low that Phione is better to be never used. It can't learn any seriously useful moves either, being almost worth nothing.

POWERFUL: RAYQUAZA

Rayquaza was a monster before Pokémon Omega Ruby and Alpha Sapphire, and it became a much bigger threat after that. Rayquaza and Salamence remain the strongest Pokémon from Gen III, and both of them got Mega Evolutions. Mega Rayquaza can counter the permanent weather changes from Primal Groudon and Primal Kyogre. It also hits like a truck, dealing a lot of damage, having great coverage, and not being weak to many attacks. Rayquaza pops up a lot in competitive play to either counter other Pokémon or to carry an entire team.

WEAK: REGIGIGAS

Regirock, Regice, and Registeel were part of the legendary trio in Gen III. However, their existence merely pointed to the awakening of an even larger golem, Regigigas in Gen IV. Despite us waiting an entire generation to see the lord of the golem trio, it wasn't worth the wait. It has the ability Slow Start, which cuts its attack and speed stat in half for five turns when it switches into combat. Its stats would've been otherwise decent, but the ability alone makes it a serious disappointment.

POWERFUL: GROUDON

Groudon was a powerful Pokémon when it was first introduced. It had some dangerous ground-type attacks and the stats to back it up. However, it was a Pokémon that used the sun in battle but didn't get STAB on its fire moves because it wasn't a fire type. That changed in Omega Ruby when Groudon was given a Primal Reversion to become Primal Groudon. It gained the fire typing and could summon permanent sunlight with its ability. Groudon suddenly became a much bigger threat.

WEAK: REGI TRIO

Regirock, Regice, and Registeel had cool designs and it took a while to find them in the games. However, the adventure necessary to obtain them wasn't worth it because of how poor they were in battle. None of them had great stats or great move pools. Their single typings only shrunk their move pools. They each had a lot of weaknesses to common types. Furthermore, any potential they had was wasted by Pokémon that did everything they could do but much better.

POWERFUL: KYOGRE

Kyogre was already powerful before it gained a Primal Reversion due to it getting STAB on its rain-enhanced water moves, but it became a larger threat after Alpha Sapphire's release. What makes Primal Kyogre such a beast is that its stats are increased to give it some serious attack power on top of keeping its bulk. This makes Kyogre an unpredictable asset to any team. There's no telling what someone will use a Primal Kyogre for, because it excels at just about anything.

WEAK: VIRIZION

Virizion is the weakest of the Swords of Justice from Gen V, and none of them are particularly that great to begin with. The reason Virizion is at the bottom is because it takes a lot of damage from physical attacks but doesn't have the defense to take a hit. What's worse is its grass and fighting type, making it four times weak against flying attacks. Considering a lot of popular Pokémon are flying types with much greater speed, Virizion has no chance. Even its Z-move can't save it.

POWERFUL: ARCEUS

It makes sense that the god of Pokémon would climb high up the tier lists. Arceus has everything you'd want in a Pokémon: great stats, a great moveset, and flexibility. With a simple item, Arceus can change to any type in the game. This type also changes the type of its signature move, Judgment, guaranteeing a STAB boost at all times. Even without a type change item, Arceus is a sheer monster that many players don't know how to handle.

WEAK: MESPRIT

Mesprit is one of the legendary Pokémon trio from Gen IV, and it's every bit as underwhelming as you might expect. The big problem with Mesprit is that its stats are working against it at from all angles. There is just no redeeming quality to Mesprit. While a single Psychic type doesn't give it a lot of weaknesses, it doesn't have the attack or defense to make good use of it. When Pokémon like Mewtwo and Deoxys already exist, there's no reason to choose Mesprit over them.

POWERFUL: YVELTAL

Yveltal is a deity of chaos and was one of the legendary Pokémon introduced in Gen VI with Pokémon X and Y. Yveltal lives up to its moniker by having some deadly stats. This dark and flying type wyvern has the stats to work in just about any position on a team. Yveltal has a wide move pool and has the power to back it up. It was also given a signature move in the form of Oblivion Wing, a powerful flying attack that recovers health to the user.

WEAK: RAIKOU

Raikou has respectable speed and an excellent array of electric attacks to choose. However, its attack and defense are both lacking, which make it an ineffective glass cannon at best. All it would take is a well-timed ground attack. Both Entei and Suicune have certain attributes that bump them a bit higher. Raikou seems to be lacking in more areas than its counterparts. When bulky Pokémon dominate the meta, there's no reason to pick a Pokémon that can't punch through them.

POWERFUL: HO-OH

Ho-Oh has access to one of the most useful abilities in the entire game, Regenerator, which gives it 1/3 of its HP back every time it switches out. This wouldn't be useful if Ho-Oh wasn't versatile or couldn't take a hit, but that's not the case. Ho-Oh has the stats to work as both an offensive and defensive Pokémon. It has a wide move pool with some of the most powerful fire attacks in the game. The Johto Region has a lot of reason to worship it.

WEAK: ARTICUNO

Moves that penalize switching Pokémon, like Stealth Rock, are popular in competitive play. That's why it's important to have ways around it with any team. However, this move would practically neutralize Articuno, which is four times weaker to that move thanks to being an ice and flying type. To make matters worse, Articuno doesn't have the defense to take a hit or the speed to attack first before going out. It needs help whenever it comes out, and that's a bad sign for any Pokémon.

POWERFUL: LUGIA

Lugia is one of the best tanks in Pokémon bar none. The reason for this is not only because of its tanky stats, but because of its ability Multiscale. When Lugia is at full HP, the damage of any attack that hits it is cut in half. This means that Lugia is not a Pokémon that will get taken out in one hit (it's nearly impossible to do so). Couple this with Lugia's capability to heal itself as well as apply dangerous status effects to any opponent, and it becomes a major nuisance to any opponent.

WEAK: CRESSELIA

Cresselia's stats aren't bad. As a matter of fact, it could work as a tank with its defensive stats in the right situation. However, the problem is that Cresselia doesn't excel at anything else to make it a threat. It essentially becomes a damage sponge that can't do much of anything else. It would probably fall in battle to a Dark-type Pokémon in at least two turns. Furthermore, Cresselia has some fairly low speed and attack, meaning that it won't be securing any KOs.

POWERFUL: KYUREM WHITE

Kyurem White is the Godzilla of the Pokémon series. It has a ridiculous special attack stat, which is so high that Kyurem White could wipe out just about any Pokémon in one hit. It can punch through some of the game's major tanks, and do so without breaking a sweat. This is helped by its ability, Turboblaze, which makes all of its attacks ignore other Pokémon's abilities. Imagine having a destructive Pokémon that could ignore Lugia's Multiscale.

WEAK: GUZZLORD

Guzzlord has an astronomical HP stat, making it a tank right from the start. The problem with it is that none of its other stats rise to the occasion, making it essentially a sponge and nothing else. Its ability is also deemed useless thanks to its stats. Beast Boost raises the tier of highest stat anytime it knocks out a Pokémon. However, good luck knocking out any opponents with Guzzlord's measly attack and speed stats. It certainly takes the "Ultra" out of Ultra Beast.

POWERFUL: XERNEAS

Fairy types focus a lot of offensive play, and that style is bolstered by Xerneas' ability, Fairy Aura, which raises the attack power of any Fairy attack on the field. That's just the tip of the iceberg. Xerneas has all-around great stats, both offensively and defensively. Because of this, it's undoubtedly the best Fairy-type in the game. There are others that function as tanks and some that functions as late-game sweepers, but Xerneas works in just about all of those categories.

WEAK: COSMOG

Cosmog is the first "basic" legendary Pokémon. After being trained, Cosmog can level up and evolve into Cosmoem before evolving into either Solgaleo or Lunala. Despite being an extremely rare Pokémon, Cosmog doesn't offer anything to the table in terms of battle. Every single one of its stats is a disappointment. Then there's the fact that it can't damage an opponent. It can only learn Splash and Teleport, which it makes it somehow less useful than a Magikarp. Keep in mind this is supposed to be a legendary Pokémon.