It's no secret that Legendary Pokemon are extremely powerful. But, they're far from equal. After eight generations of Pokemon, there have been quite a few Legendaries introduced, and some of them have a lasting claim to the pantheon of power, while others tend to kind of... trail behind.

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It's fascinating to see which Legendaries are uber-strong, and which aren't. Plus, it can play a role in whether you add them to your team or not. Based mostly on base stats, but also with other considerations, here are the most powerful and weakest Legendaries.

Updated on July 2, 2021 by Michael Christopher: Since its initial publication, a lot has happened in the world of Pokemon, so this post was a bit out of date. We've updated it to keep it current, as well as to fix up the formatting and make it more readable.

10 Worst: Regigigas

regigigas in the pokemon anime

Poor Regigigas. At face value, this Normal-type from Gen IV seems like it would be an absolute beast in battle. And, to an extent, it is. According to the Pokedex, Regigigas has the power to move entire continents with its strength. That, combined with its 670 base stat total (including a massive 160 Attack stat), makes it seem like Regigigas is unstoppable.

However, it's absolutely ruined by its ability. Slow Start, the only ability Regigigas can have (no secondary or hidden abilities to save it here), cuts its Attack and Speed in half for the first five turns it appears in battle. In the competitive online scene, Regigigas will be taken down before those five turns are even over.

9 Best: Crowned Zacian and Crowned Zamazenta

Pokemon Zacian and Zamazenta

Two of the newest Legendaries on this list, Zacian and Zamazenta are incredibly strong, but specifically in their Crowned forms. By holding the Rusted Sword (Zacian) or Rusted Shield (Zamazenta), they'll transform into these forms and gain the Steel-type.

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Both of these new forms are fantastic in battle. They both have a base stat total of a whopping 720, which is among the highest in the series. For Crowned Sword Zacian, that includes an absolutely staggering 170 Attack and a lightning-fast 148 Speed. Crowned Shield Zamazenta distributes the 720 points a little more flatly across the six stats, but boasts an incredible 145 Defense and Special Defense, along with a nice 130 Attack and 128 Speed.

8 Worst: Base Form Calyrex

Pokemon - Calyrex on the crown tundra

Joining Zacian and Zamazenta in being from Gen VIII is Calyrex, who was added as part of the Crown Tundra DLC expansion. Also like the Hero Duo, Calyrex has different forms. When it fuses with Spectrier or Glastrier, it becomes Shadow Rider Calyrex or Ice Rider Calyrex, respectively. Both of Calyrex forms are very, very powerful.

However, in its base form, unfused, it's very disappointing. In this form, its base stat total is a meager 500 points, which is of course not the worst in the game, but it is abysmal for a Legendary. This is the same base stat total as Scyther, which can still evolve. Additionally, the Psychic/Grass-type of base form Calyrex ties for the type combo with the most weaknesses. Yikes.

7 Best: Primal Kyogre and Primal Groudon

pokemon - a battle between Primal Groudon and Primal Kyogre

In Gen VI, when a bunch of Pokemon received Mega Evolutions, Groudon and Kyogre received something very similar: Primal Reversion. These alternate forms come with a huge stat increase, new abilities, a new type for Groudon (sorry Kyogre), and new looks. With an absolutely astounding base stat total of 770 each, Primal Groudon and Primal Kyogre have the second-highest base stat total of any obtainable Pokemon.

For Primal Groudon, this means a ridiculous 180 Attack, 160 Defense, and 150 Special Attack. For Kyogre, Primal Reversion gives it 180 Special Attack, 160 Special Defense, and 150 Attack. Between the two of them, though, Primal Kyogre will probably win, as Primal Groudon is double-weak to Water-type moves.

6 Worst: Cosmog

Pokemon - Cosmog's overview screen in sword & shield

Is this even fair? Poor Cosmog is the first Legendary Pokemon that can evolve to be introduced to the series. In Sun & Moon, this little friend will evolve into Cosmoem before evolving into either Solgaleo or Lunala, depending on your game version. Before evolving, though, it has absolutely dismal stats with a base stat total of only 200 — putting it on par with Magikarp, Feebas, and Scatterbug.

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Just to add insult to injury, Cosmog can only learn two moves: Splash, and Teleport. You'll want to evolve it as soon as possible, and then hurry to do it again, because Cosmoem is also pretty bad.

5 Best: Ultra Necrozma

Ultra Necrozma spreads its massive wings as it emerges from Ultra Space.

Cosmog's eventual evolutions, Solgaleo and Lunala, are rather powerful, especially compared to their base form. Their power is, unfortunately, used by Necrozma to make itself stronger too, eventually making itself one of the strongest Pokemon in the games.

By fusing with Solgaleo or Lunala, Necrozma will become Dusk Mane Necrozma or Dawn Wings Necrozma, respectively. Then, by using Ultra Burst, it'll transform into the ultimate final form: Ultra Necrozma. This behemoth doesn't just have a base stat total of 754 (including 167 in both Attack and Special Attack), but it will be able to use the Z-Move Light That Burns The Sky, which does has 200 base power, ignores abilities, and uses whichever attack stat is currently higher. Oh, and because it's a Z-Move, it basically never misses.

4 Worst: Kubfu

pokemon kubfu

Cosmog, the first evolvable Legendary Pokemon, was soon followed by Fighting-type Kubfu in the Isle of Armor DLC expansion of Sword & Shield. This small bear is cute and ferocious, but it unfortunately doesn't have the stats behind its attitude. A base stat total leaves this poor little Pokemon behind many middle stages and even a Baby Pokemon — Munchlax.

However, it does have a nice 90 in Attack, which is nothing to scoff at. When Kubfu evolves, it'll evolve into one of two different forms of Urshifu, and then it definitely holds its own in battle. Until then, though, this rowdy Pokemon's going to do the best it can.

3 Best: Mega Rayquaza

Pokemon ORAS Animated Trailer Mega Evolution Rayquaza

It's no secret that Mega Rayquaza ties with the Mega Mewtwo pair for the highest base stat total of any obtainable Pokemon, with a massive 780. For Mega Rayquaza, this is distributed as 180 Attack and Special Attack, 115 Speed, 100 Defense and Special Defense, and 105 HP. When all of your base stats are three digits, that's impressive. RELATED: Pokemon: The Types With the Most Resistances

What makes Mega Rayquaza even more fearsome is that it's the only Pokemon that doesn't need to hold an item to Mega Evolve. Rayquaza Mega Evolves with the move Dragon Ascent. This frees up its held item slot for whatever you want, giving Mega Rayquaza even more prowess over other Mega Evolutions.

2 Worst: Moltres

Moltres In Sunset, Pokemon Go

Moltres is definitely not a weak Pokemon by any means, but when looking at the lowest tiers of Legendaries, you'll definitely find it. A member of the original Legendary Trio, the Legendary Birds of Kanto, Moltres is a Fire/Flying-type and has a base stat total of 580. This is decent, but it pales in comparison to other Legendaries, which often exceed 600. Just one generation later, Ho-oh would come in with the same typing and a higher base stat total of 680.

Moltres was arguably trumped by some of its contemporaries before Ho-oh even came along, though. Charizard has, in many ways, much more viability in battle while having the same type combination. Even Arcanine and Rapidash are better choices if you need a Fire-type, and they don't come with the double weakness to Rock that Moltres has.

1 Best: Mega Mewtwo

mega mewtwo x and mega mewtwo y with the mega evolution symbol overlaid on a game background

Though it ties with Mega Rayquaza's base stat total, Mega Mewtwo's two variants are easily the most powerful Legendary Pokemon. Of course, Eternamax Eternatus has a higher base stat total, but it's unobtainable, and for what it's worth, it's nowhere near as iconic as Mewtwo.

Both Mega Mewtwo have a base stat total of 780. Mega Mewtwo X, which adds the Fighting-type to Mewtwo's existing Psychic-type, has 190 in Attack (the highest of any Pokemon), 154 in Special Attack, 130 in Speed, and above 100 in everything else.

Mega Metwo Y has a single stat that falls under 100 — its Defense, at 70 — but it more than makes up for it elsewhere, like its 150 Attack, 140 Speed, and downright baffling 194 Special Attack (again, the highest of any Pokemon).

Pair all of this staggering strength with the iconic role Mewtwo has held over the past 25 years, and you've definitely got the single best Legendary Pokemon on your hands.

NEXT: The Best Non-Legendary Pokémon, Ranked