Following the release of Pokémon X & Y, the franchise introduced Mega Evolution, revolutionizing Pokémon battles with significant stat boosts and type-changes for powerful Pokémon. Despite being overshadowed by Z-Moves in later games, Mega Evolution remains a key feature in the series.

However, not all Pokémon benefit from these advantages. Some Mega Evolutions are considered ineffective, wasting their one-time use in battle. Weak Mega Evolutions typically reflect poor ability choices rather than making a Pokémon fundamentally flawed. Below is a list highlighting some of the weakest and strongest Pokémon Mega Evolutions, enabling players to choose wisely.

16 Mega Diancie

Weakest

As a mythical Pokémon, Diancie is inherently powerful, and expectations soared when its Mega Evolution was announced. Visually, Diancie’s Mega Evolution is nothing short of a masterpiece while boasting high attack and special attack stats.

Upon evolving into Mega Diancie, its offensive capabilities increase, but its once robust defensive stats decrease significantly. Coupled with its low HP, Diancie is particularly susceptible to powerful attacks, especially from Steel types. Despite its strengths, these vulnerabilities place Mega Diancie among the weaker Mega Evolutions, though it is still the strongest in that category.

15 Mega Audino

Weakest

As the signature Pokémon of Nurse Joy in the Pokémon anime, Audino primarily supports other Pokémon with its healing-centric moveset. Its Mega Evolution shifts to Fairy type and gains a modest 20-point increase in special attack, with significant boosts to its defense and special defense. This reinforces its role as a defensive tank that absorbs damage and heals allies.

While this setup is advantageous in double or multi-battles, it could be more effective in multiple battles. If Mega Audino uses the team's only Mega Evolution opportunity, the player must compensate for its limited offensive capabilities with more powerful attackers.

14 Mega Houndoom

Weakest

Mega Houndoom stands out in design among Mega Evolutions but needs more combat effectiveness. It receives a boost for its special attack and defense, but its main drawback is its solar power ability.

This ability only activates in sunny weather, typically requiring setting up with Sunny Day or having another Pokémon with the Draught ability. Both strategies potentially waste valuable turns and leave Mega Houndoom exposed.

Additionally, Solar Power drains Mega Houndoom's HP each turn it's active, making it a risky choice. It is particularly vulnerable to super-effective or critical hits. This combination of high risk and high maintenance makes Mega Houndoom a mixed bag in battle scenarios.

13 Mega Scizor

Weakest

Scyther in Pokémon X & Y and its evolution, Scizo, are among the strongest Bug-type Pokémon. Scizor receives a Mega Evolution in Pokémon X & Y that significantly boosts its attack. Mega Scizor retains the Technician ability (or changes if the prior ability was Swarm), which enhances moves with a power of 60 or less, rather than evolving to an ability that might complement its new, more powerful moveset.

Mega Scizor's Technician ability does not boost the power of variable moves like Pursuit or Fury Cutter.

While Technician is effective for some of Scizor's earlier moves, it becomes underwhelming and less beneficial as it learns stronger moves like X-Scissor and Iron Head, which do not benefit from Technician. An ability like Tough Claws, which boosts contact moves, would be more advantageous for Mega Scizor and aesthetically fitting, given its intimidating appearance.

12 Mega Abomasnow

Weakest

Abomasnow and its pre-evolution Snover are unique as the only Ice/Grass-type Pokémon. Upon Mega Evolving, Abomasnow gains significant boosts to its already impressive attack and defense but sacrifices speed. Ideally, its Mega Evolution would grant an ability to mitigate this drawback, such as Thick Fat.

Instead, it retains Snow Warning, an ability it already activates before Mega Evolving. This does little to enhance its new form and leaves it vulnerable to faster Pokémon, especially against the best Fire-type Pokémon. Abomasnow’s Mega Evolution doesn’t fully capitalize on its potential, failing to address its critical speed issue.

11 Mega Gyarados

Weakest

The Mega Gyarados Pokémon is notably the most disappointing of all the Mega Evolutions in Pokemon X & Y, both in design and battle potential. While it gains significant boosts in offense and defense upon Mega Evolving, it also becomes more vulnerable.

Originally, Gyarados was weak against Electric and occasionally Rock-types, but after Mega Evolving, it loses its Flying-type advantage, exposing it to Grass and Ground-type moves. Additionally, it gains new weaknesses when facing Fighting, Bug, and Fairy Types.

Many Pokémon fans believe that Gyarados should have been a Water/Dragon-type, arguing that this would have been more fitting and provided better resistance to Grass and Electric types.

10 Mega Absol

Weakest

Playing with Absol, a formidable Pokémon with high attack and speed stats, is even more lethal as a Mega Evolution. The Mega form's Magic Bounce ability can reflect status-lowering moves, conditions, and entry hazard moves like Stealth Rock and Toxic Spikes.

However, Mega Evolving Absol carries risks. Unlike most Mega Evolutions, Absol doesn't gain any defense or special defense boosts, remaining quite fragile. As a result, if it fails to knock out its opponent, it's likely to be defeated in a counterattack. While Mega Absol can be a game-changer when used effectively, its unpredictability and weak defenses often make it a risky choice for your single Mega Evolution.

9 Mega Banette

Weakest

Bannette, one of only three Ghost-type Pokémon capable of Mega Evolution, struggles to stand out despite having the highest attack stat among Ghost-types. In comparison, Mega Banette seems weaker than Mega Gengar. Its ability, Prankster, which prioritizes non-attack moves, does not synergize well with its limited move pool, though there are exceptions like Destiny Bond and Grudge.

Ultimately, Mega Banette often wastes a Mega Evolution slot. Its high attack stat can be replicated with items like a Life Orb, making using a Mega Evolution on Banette less advantageous, especially considering the better choices available with superior type advantages.

8 Mega Venasaur

Strongest

Thanks to Mega Evolution, all the Gen I Pokémon starters, including Charizard, Blastoise, and Venusaur, receive significant power boosts. Charizard and Blastoise see increases in firepower, while Venasaur gains major enhancements in its defensive abilities.

By Mega Evolving, Mega Venasaur transforms into a formidable tank with well-rounded enhancements, particularly in defense and special defense. Additionally, Mega Venusaur's standard Grass-type ability, Overgrow, is substituted for the Thick Fat Ability. This new ability reduces the damage from its primary weaknesses, fire, and Ice-type attacks by 50%, turning these significant threats into minor inconveniences.

7 Mega Charizard X & Y

Strongest

Since the release of Pokémon Red & Blue, many fans have been puzzled by Charizard's lack of a Dragon typing despite its draconic appearance. Fortunately, Pokémon X & Y introduced a solution by creating a Dragon-type Charizard through Mega Evolving.

As Mega Charizard X, it benefits from increased attack, defense, and special attack stats. Additionally, its Tough Claws ability enhances the power of contact moves like Flare Blitz and Dragon Rush, enabling Mega Charizard X to inflict substantial damage.

While unique from its X counterpart, Mega Charizard Y is equally formidable. It doesn't receive as significant attack and defense boosts, but it compensates with prominent enhancements to its special attack and a slight increase in defense. Moreover, its Draught Ability allows it to use Solarbeam instantly, effectively countering water types. YouTuber TheAuraGuardian does a direct comparison of Mega Charizard X & Y, overviewing their typing, stats and abilities, and movesets.

6 Mega Altaria

Strongest

Altaria combines elegance with formidable power, making it a valuable ally for any trainer, especially when boosted by Mega Evolution. Upon transforming into Mega Altaria, it gains a Dragon/Fairy typing, eliminating its vulnerability to Dragon-type moves. However, this change exposes Altaria to a new weakness against Steel-type Pokémon, which is fortunately mitigated by its ability to use support moves like Cotton Guard, enhancing its endurance.

Mega Alteria becomes nearly impenetrable, capable of withstanding almost any physical attack, making it a mighty flying fortress. Additionally, its Pixilate ability converts powerful normal-type moves like Hyper Beam and Giga Impact into Fairy-types and boosts their power by 30%, further amplifying its offensive capabilities.

5 Mega Gengar

Strongest

Gendar, already a powerhouse since its deputy in Pokémon Red & Blue, ascended to new heights with its Mega Evolution, becoming one of the strongest Pokémon in the game. Mega Gandar receives a significant boost to its special attack and gains the Shadow Tag ability, which prevents non-Ghost-types from switching out. This drastically limits your opponents' strategies, giving you an advantage in battle.

The true peril of Mega Gengar lies in its potential to combine this trapping ability with moves like Destiny Bond and Perish Song. These combinations can ensure that even if an opponent manages to knock Mega Gengar out before the countdown ends, the Pokémon responsible will also be eliminated.

Due to its overwhelming power and strategic dominance, Mega Gendar has been widely regarded as so deadly and disruptive that fans globally have advocated for its ban from Pokémon champion tournaments.

4 Mega Aggron

Strongest

Mega Aggron stands out as one of the most powerful Steel types, boasting some of the highest defensive stats in the game. By losing its Rock-type upon Mega Evolving, Mega Aggron reduces its vulnerabilities to just Ground, Fire, and Fighting types. Its Filter ability further enhances its resilience by significantly decreasing damage from super-effective moves.

Although Mega Aggron's speed is relatively slow, this can be mitigated with strategic moves. For example, using the move, Automatize, increases Mega Aggron’s speed at the cost of its weight. This enables it to deliver first strikes with powerful blows like Iron Head or Head Smash. Despite its slower speed, Mega Aggron's robust defenses allow it to withstand nearly any attack and retaliate forcefully, especially with a well-timed Metal Burst.

3 Mega Lucario

Strongest

Mega Lucario is the most iconic example of Mega Evolutions in Pokémon X & Y and the first Mega Evolved Pokémon encountered by players. Known for its strikingly distinguishable design and competitive prowess, Mega Lucario becomes particularly powerful due to its high attack and special attack stats. Its Adaptability ability further amplifies these attributes, which enhances the power of moves that share its type.

With Adaptability, alongside the same-type attack bonus (STAB), Mega Locario's same-type moves see their power doubled. For example, the Close Combat move normally has a power of 120, but with these bonuses, its power effectively increases to 240. This immense power makes Mega Locario nearly unbeatable in battle without a Pokémon with robust defensive stats.

2 Mega Mewtwo X & Y

Strongest

Mewtwo is unique for having two Mega Evolutions, each with its own set of strengths. Mega Mewtwo X transforms into a Fighting-type and Psychic-type Pokémon, gaining a massive increase to its attack stat and a modest enhancement in defense, while retaining its high special attack. This allows it to effectively use moves like Psychic and Aura Sphere.

In contrast, Mega Mewtwo Y, despite a slight decrease in defense from 90 to 70, receives improvements in its attack, defense, and speed, along with a significant boost to its special attack. This makes it just as formidable, if not more so, than its counterpart.

Both of Mewtwo’s Mega Evolutions are incredibly powerful, making it difficult to choose between them. Regardless, opponents face a tough challenge in countering Mewtwo once it unleashes its Psystrike move. Ace Trainer Liam compares the two Mega Pokemon against one another in battle, showcasing their differing strengths and weaknesses.

1 Mega Rayquaza

Strongest

Mega Rayquaza, alongside Mega Mewtwo X and Y, boasts the highest base stats as the strongest Pokémon from X & Y. A significant advantage of Mega Rayquaza as a team member is that it does not require a Mega Stone to evolve, freeing up the item slot for other beneficial combat items. However, it must know its signature move, Dragon Ascent, to Mega Evolve.

Upon evolving, it gains the Delta Stream ability, which neutralizes all move-types typically effective against Flying-types, leaving only Dragon, Ice, and Fairy-type moves as effective counters. With its overwhelming attack power and nearly impenetrable defense, Mega Rayqyaza is an exceptional force in battle, challenging for any opponent to overcome in Pokémon X & Y.

Source: TheAuraGuardian/YouTube, Ace Trainer Liam/YouTube