10 Strongest Legendary Pokémon In The Anime Series, Ranked

Aside from being some of the strongest beings in the iconic Nintendo franchise, Legendary Pokémon are incredibly rare, not just in the video games but in the anime as well. It's not very often that Ash Ketchum and his various traveling companions encounter these Pokémon, as it usually happens only during the climaxes of season-long story arcs or in special episodes coinciding with the releases of "Pokémon" games. Nevertheless, every Legendary Pokémon has appeared in the anime at least once, whether in mainline seasons or feature films. 

Since most "Pokémon" games release in paired versions with their own Legendary mascots, many Legendary Pokémon are closely tied to counterparts with similar power levels. For instance, Generation IV's Dialga and Palkia can both alter time and space, respectively, but one doesn't exist without the other. In many cases, a third member of a Legendary trio is portrayed as balancing or surpassing the others in power. 

Before any diehard "Pokémon" fan leaps to correct this list by pointing out the exclusions of powerful Pokémon like Arceus, Hoopa, and Deoxys, let us remind them that those are technically Mythical Pokémon, an even rarer subsection of Pokémon than your average Legendary. Without further ado, let's take a legendary look at some of the strongest Pokémon in the anime thus far. 

Silvally is rare even among Legendary Pokémon, given that it is the evolved form of another Pokémon, Type: Null. Appearing first in "Pokémon Sun & Moon," Type: Null is an artificially created Pokémon, with Silvally serving as a slightly weaker version of the Mythical Pokémon Arceus. Much like Arceus' Plates, Silvally can change types depending on which Memory item it holds. In the anime, Silvally is just as one-of-a-kind, but appears as Gladion's ace in "Pokémon the Series: Sun & Moon."

Silvally's role in the series is similar to that of the games, having been created by the Aether Foundation to combat the threat of extra-dimensional Ultra Beasts. In battle, Gladion proved on numerous occasions to be a fearsome adversary of Ash, swiftly defeating his Lycanroc with the help of Silvally's Legendary-level power. 

Given it was specifically designed to battle Ultra Beasts and rival Legendary Pokémon in strength, Silvally is easily one of the most powerful Pokémon owned by a regular trainer in the anime. Even so, even a powerful man-made Pokémon ended up being no match for the power of Ash's own Pikachu during the Manalo Conference. 

Lugia is the mascot of "Pokémon Silver" and the second-generation counterpart to Ho-Oh, the Legendary Pokémon that Ash witnesses in the very first episode of the anime. However, Lugia plays a prominent role not only in the series itself, but also in the second film, "Pokémon the Movie 2000: The Power of One." In the movie, Pokémon archaeologist Lawrence targets Lugia by enraging the three Legendary Birds — Articuno, Zapdos, and Moltres — forcing Lugia out of hibernation to quell the disturbance.

As you might expect, Lugia possesses a power greater than the other three Legendary Pokémon combined, but not by much. Lawrence is still able to overwhelm Lugia enough to injure it, leaving it susceptible to his capture. Lugia still manages to resist capture long enough for Ash and his friends to help nurse it back to full health and take down Lawrence's airship. 

Another Lugia also appears in "Pokémon the Series: Gold & Silver," aptly named Silver. This young Lugia was captured by Team Rocket to draw out its parent, the elder Lugia, in order to capture it. Though Lugia creates devastating weather in its outrage, Team Rocket is successful in its plan... at least for a little while. Like in the movie, human interference can temporarily subdue Lugia, but when set free, it's a force of nature to be reckoned with. 

Mewtwo probably ranks at the top of a list of the most iconic Legendary Pokémon, but as far as the anime is concerned, its power is more akin to a user of dark magic rather than a force of nature like many other Legendaries are. Nevertheless, Mewtwo has one of the more memorable anime appearances in the very first feature film of the Ash Ketchum era: "Pokémon: The First Movie – Mewtwo Strikes Back."

In the movie, Mewtwo summons some of the world's strongest trainers — at least those established by the franchise at that point — using its psychic powers to create a storm that prevents many of them from reaching the island where it resides. These psychic powers are far beyond what we've seen from other Psychic-type Pokémon in the series. As if that wasn't enough, Mewtwo also creates clones of these powerful trainers' Pokémon that are superior to them in strength.

It's only Ash's heroic sacrifice that convinces Mewtwo to cease its terror, not because any trainer or Pokémon was able to actually defeat it. Mewtwo later returns in "Pokémon Journeys: The Series," once again easily defeating both Ash's and Goh's Pokémon. It may not possess the cosmic, Earth-shaking abilities of some other Pokémon on this list, but its sheer battle strength still sets it apart, especially among first-generation Pokémon. 

Necrozma is the rare example of a mainline series Legendary Pokémon that has a more prominent role in the actual series rather than making its debut in a feature film. The Psychic-type Pokémon is closely tied to the Ultra Beast phenomenon. Its origins are unknown, but it is capable of traveling between dimensions. In the games, Necrozma feeds off the energy of Solgaleo and Lunala, using its violent power to assume stronger forms and ultimately become a being made of pure light. 

Necrozma appears in "Pokémon the Series: Sun & Moon" when the Aether Foundation's research into Ultra Beasts accidentally summons the powerful Legendary Pokémon. Necrozma then merges with Lunala and kidnaps Solgaleo, a.k.a. Nebby, through an Ultra Wormhole, forcing Ash and his friends — acting as the "Ultra Guardians" — to venture into Poipole's dimension to rescue it. 

Even though there's a point in the multi-episode arc where Necrozma seems too powerful to be beaten, the Ultra Guardians eke out a victory by using their Pokémon's extra-powerful Z-Moves, filling Necrozma with enough light and energy to return it to its more peaceful original form. Suffice it to say, Necrozma's incredibly powerful... but only when it's really angry. 

Rayquaza has the benefit of being a fan-favorite Legendary Pokémon, serving as both the mascot of "Pokémon Emerald" as well as being the third and most powerful member of Hoenn's weather trio with Kyogre and Groudon. Whereas Kyogre and Groudon can summon rain and drought, respectively, Rayquaza acts as a peacekeeper between the two powerful Pokémon. It also serves as the rival of the extraterrestrial Psychic-type Deoxys in one of the third-generation films. 

Though Rayquaza showcases devastating power on the big screen, even stronger versions of the Legendary Pokémon have since appeared in the anime. A shiny Rayquaza notably appeared in the latest anime series, "Pokémon Horizons," as part of a group of six heroic Pokémon separated from their trainer over 100 years ago, and, most recently, was caught by Roy, one of the series' protagonists. However, neither the Shiny Rayquaza nor the Rayquaza from "Pokémon: Destiny Deoxys" is the strongest version of the Legendary Pokémon to appear in the anime. 

That honor goes to the Rayquaza from the "Mega Evolution Special" episodes of "Pokémon the Series: XY," where it showcases its incredibly powerful Mega-Evolved form and defeats both Alain and Steven, two of the strongest trainers in the anime. Resisting the combined power of two incredibly strong trainers is an appropriate power scaling for the Legendary Pokémon, who also happens to be one of the strongest Pokémon in the video games, as well. 

While most Legendary Pokémon, especially version mascots, are more powerful as duos rather than on their own, the sixth-generation Legendaries are the exception. Yveltal, a Dark- and Flying-type Pokémon, is known as the Destruction Pokémon, and the name is not an over-exaggeration. In "Pokémon the Movie: Diancie and the Cocoon of Destruction," Yveltal is portrayed as a catastrophic force capable of decimating entire environments. 

After its hundred-year-long slumber was disturbed by thieves fighting over the Mythical Pokémon Diancie, Yveltal caused devastating damage to the Allearth Forest with a single move, Oblivion Wing, powered by its Dark Aura ability. Fortunately, Ash, Serena, Clemont, and Bonnie are protected from the forest's petrification thanks to Diancie's Mega-Evolved form. It's only thanks to the summoning of Yveltal's Legendary counterpart, Xerneas, that the calamity is able to be reversed. 

Though it takes an entire other Legendary Pokémon to calm it down, when Yveltal is enraged, it has proven its ability to cause some seriously terrifying devastation, as evidenced by the movie in which it appears. It certainly would make for an intimidating Pokémon to bring to life in a "Pokémon" live-action series. 

As previously mentioned, there is only one Pokémon that's been known to quell Yveltal's destruction: Xerneas, the Life Pokémon. As the mascot of the sixth-generation game "Pokémon X" and the franchise's first Fairy-type Legendary Pokémon, Xerneas embodies peace and prosperity in the French-inspired Kalos region thanks to the unique Fairy Aura ability that enhances its own power. 

Like Yveltal, Xerneas plays an integral role in "Pokémon the Movie: Diancie and the Cocoon of Destruction," bestowing Diancie with the Fairy Aura ability that it later uses to save Ash and his friends from Yveltal's wrath. Xerneas also arrives at the eleventh hour to calm Yveltal's rampage and reverse its destructive effects. Doing so seemingly takes a lot of Xerneas' power, as it enters hibernation shortly after. 

A similar sacrificial act is depicted in the "Pokémon the Series: XY" special "The Legend of X, Y, and Z," which features a flashback of Xerneas restoring a barren land destroyed by Yveltal. However, this flashback also reveals some limits to Xerneas' power, as the Legendary Pokémon was unable to save a young village girl, Aila, from Yveltal's wreckage. 

Even the strongest Pokémon trainers get chills down their spines when they think of facing the Renegade Pokémon. The mascot for "Pokémon Platinum," Giratina is the third member of the creation trio alongside Dialga and Palkia. Whereas those other two Legendaries rule over time and space, respectively, Giratina is their violent counterpart, banished to the Distortion World (called the "Reverse World" in the anime) to protect the world of Pokémon.

In the anime, Giratina plays a central role in the movie "Pokémon: Giratina and the Sky Warrior," seeking revenge for the effects that Palkia and Dialga's constant warring has on the Reverse World. It ambushes Dialga and nearly drags it into the Reverse World with the move Shadow Force, but Shaymin ultimately thwarts the attack before Giratina becomes trapped in a time loop created by Dialga. It ends up being a big mistake on Shaymin's part, having angered this demonic Legendary.

After allying with the villainous Zero, a sycophantic scholar of the Reverse World, Giratina is betrayed, its own dimension-destroying powers seized by a human. Thankfully, Ash and his friends stop Zero, restoring Giratina's powers and helping the Legendary Pokémon undergo a change of heart. It's for the best because an angry, vengeful Giratina is one of the most dangerous Legendary Pokémon in the franchise.

It's hard to imagine any Legendary Pokémon having an edge over Xerneas and Yveltal, the literal personifications of life and death. Nevertheless, the sixth-generation games introduced Zygarde, a Legendary Pokémon that has played a major role in a number of the video games, but most notably in one of the best TV shows based on Nintendo games, "Pokémon the Series: XY." 

As an amalgamation of individual Zygarde Cores, Zygarde's power level varies depending on its form. In its Complete Form, Zygarde is shown to be even more destructive than Yveltal, especially with the use of its devastating move Core Enforcer. When Team Flare attempts to restore the Pokémon world to a primitive state by activating a Complete Form Zygarde, the only way to stop it is with the help of another Zygarde — the friend of Ash known as Squishy. 

Furthermore, the Complete Form Zygarde, known as Z2, is only stopped after Clemont destroys the machine controlling the Legendary Pokémon. If left unchecked, Team Flare might've been successful in using just one Zygarde's power to completely eradicate the entire Kalos region, and maybe even the entire Pokémon world. Knowing that Zygarde is one of the strongest Legendary Pokémon ever, even before its Mega Evolved form was revealed in the recent game "Pokémon Legends: Z-A," it's a good thing there was another Zygarde that could bring order. 

Eternatus is a difficult Pokémon to wrap your head around, whether because of its unconventional role in the story of "Pokémon Sword & Shield" or its overwhelming, extraterrestrial design. Eternatus also happens to be the largest Pokémon in the franchise, at 65 feet tall in its normal form and a staggering 328 feet tall in its "Eternamax" form.

In the anime, Eternatus' role parallels its video game counterpart, having been responsible for a legendary doomsday known as the "Darkest Day," only to be stopped by the combined strength of two kings and their Legendary Pokémon. When Macro Cosmos President Rose reawakens Eternatus to recreate the Darkest Day and restore energy to the Galar region, its power causes Pokémon across the region to spontaneously undergo the Dynamax phenomenon. 

It was only with the combined power of Zacian and Zamazenta, the ancient kings' Legendary Pokémon, that Eternatus' destructive Eternamax form could be stopped. Galar Champion Leon hopes Eternatus can be used to stabilize the region's Dynamax energy, proving just how wide-ranging its power truly is. Still, few Legendary Pokémon have come as close to causing cataclysmic damage on a global scale as Eternatus.