With the introduction of Mega Evolution in gen 6, the team over at Game Freak were able to readdress the balance of the Pokemon series. Many long forgotten Pokemon were given the chance to shine once more while some of the series' most powerful monsters were made even stronger than they already were.

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Assuming that players have access to the appropriate Mega Stones, Mega Evolution can completely change the way that battles play out and even alter a Pokemon's strengths and weaknesses. Although each Mega Evolution grants the same 100 base stat increase, how exactly these new stats are distributed can make a huge difference; as too can the Pokemon's abilities.

15 Mega Pidgeot

Mega Pidgeot (Pokemon)

Mega Pidgeot is far from being a bad Pokemon, but when compared to the other gen 1 Mega Evolutions, it just doesn't quite stack up. It does boast relatively high total base stats and its 121 speed is solid enough, although it lacks the firepower to really make its quickness count. Assuming it attacks first, it can deal some pretty decent damage, but rarely will it do enough to knock its foe out with a single hit. Given that its physical and special defense stats are both 80, it's unlikely to last long enough to get a second bite of the apple.

14 Mega Kangaskhan

Mega Kangaskhan (Pokemon)

Mega Kangaskhan's stats are fairly unimpressive, with none of its base stats exceeding 100. It does, however, have access to 15 of the 18 different move types which makes it an incredibly versatile Pokemon. Granted, it isn't great when it comes to special attacks, but with the right selection of physical moves, Mega Kangaskhan can be built to cover multiple opposition types if needed (albeit at the expense of STAB). Thanks to its Parental Bond ability, it's a very strong Seismic Toss user, but its mediocre resistances can make it difficult to fit it into a team.

13 Mega Pinsir

Mega Pinsir (Pokemon)

While Mega Pinsir's 105 speed isn't amazing, its high physical stats more than make up for it. Thanks to its 155 physical attack stat and solid learnset, it's capable of dishing out some serious damage and its 120 physical defense makes it fairly durable as well. If the other Pokemon specializes in special attacks, however, it might not be so lucky.

12 Mega Slowbro

Mega Slowbro (Pokemon)

Mega Slowbro is fairly similar to Mega Pinsir, although its 180 physical defense stat makes it considerably more durable when up against physical foes. It also leans more towards special attacks than physical, which bodes well considering that many of the strongest attacks in its arsenal fall into this category. Its biggest weakness is definitely its low speed, although this is somewhat mitigated by its high defensive stats.

11 Mega Gyarados

Mega Gyarados (Pokemon)

Despite its base stats totaling a massive 640, Mega Gyarados is a fairly underwhelming Mega Evolution. Sure, it's very strong in the physical attack department and its high special defense stat is useful too. Ultimately though, this usefulness is very situational.

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Against the right foe, Mega Gyarados can be deadly, but a strong physical attacker should have very little trouble taking it down. Worse still, its 81 speed will put it at a huge disadvantage in most encounters making it tough to justify the Pokemon's inclusion in one's team.

10 Mega Beedrill

Mega Beedrill (Pokemon)

Despite it having the lowest total base stats of any of the gen 1 Mega Evolutions, Mega Beedrill is a very solid Pokemon. It's lightning fast and has a physical attack stat of 150. Better still, when using Bug or Poison-type moves, its Adaptability ability increases its STAB (same type attack bonus) from 1.5 to 2. Its shocking defenses do make it a bit of a glass cannon, but only a handful of Pokemon are going to be able to act before it and not too many will be able to survive its opening salvo.

9 Mega Aerodactyl

Mega Aerodactyl (Pokemon)

When it comes to speedy Pokemon, they really don't get much faster than Mega Aerodactyl. With a base speed stat of 150, the fossil Pokemon is tied for the position of fastest gen 1 Mega Evolution and, as such, it's all but guaranteed to act first. Its 135 physical attack stat is solid enough already, but thanks to its Tough Claws ability, this is effectively boosted to 175 when using contact moves. It does fall short in other areas, but with that kind of speed and power, its defenses should rarely be tested.

8 Mega Blastoise

Mega Blastoise (Pokemon)

Mega Blastoise has a fairly high special attack stat, but it's fairly slow and the rest of its stats are pretty unexceptional too. While its Mega Launcher ability may seem useful on paper, there are only four moves in the Pokemon's learnset that its bonus applies to and only one of these is a water-type attack. As that move has only 60 power, moves like Hydro Pump and even surf are arguably better options.

7 Mega Venusaur

Mega Venusaur (Pokemon)

Mega Venusaur is a little faster than Mega Blastoise and also has slightly better stat distribution as well. Like its fellow starter Pokemon, it too specializes in special attacks, although it's able to back this up with some solid defensive numbers in both categories. What's more, its Thick Fat ability helps to mitigate the damage taken from two of the move-types that it's weak to. This might not be enough to save it from the very strongest Ice and Fire-type Pokemon, but it does makes Mega Venusaur a lot tougher to take down.

6 Mega Gengar

Mega Gengar (Pokemon)

Mega Gengar boasts an incredible 170 special attack stat and has access to some of the strongest ghost and psychic-type moves in the series. Its 130 speed isn't too bad either and its Shadow Tag ability makes it very difficult for its foes to flee from battle.

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The infamous ghost-type Pokemon does fall a little short in the defensive department, but, when used correctly, this needn't be a big issue. It's able to confuse and put its enemies to sleep if needed and, if all else fails, can always use Destiny Bond to take the other Pokemon down with it.

5 Mega Charizard X

Mega Charizard X (Pokemon)

Although both forms of Mega Charizard have the same total base stats, Mega Charizard X is not quite as good as the Y form. It does become a fire and dragon-type Pokemon, which can be useful in certain situations and its Tough Claws ability grants a nice bonus to contact moves as well. Ultimately though, its perfectly balanced physical and special attack stats prevent it from reaching its full potential. There will be some battles where X is the better option, but in most situations, Mega Charizard Y brings quite a bit more to the table.

4 Mega Charizard Y

Mega Charizard Y (Pokemon)

It may not look quite as cool as the X variant, but Mega Charizard Y is arguably the better Pokemon. Rather than specializing in both physical and special attacks, it instead boasts an incredible 159 special attack stat. This allows it to dish out some serious damage; especially when it has type advantage. What's more, its Drought ability can increase the damage of fire-type moves by 50% while simultaneously weakening water-type attacks by the same amount.

3 Mega Alakazam

Mega Alakazam (Pokemon)

When it comes to total base stats, Mega Alakazam is surpassed by quite a few of the other gen 1 Mega Evolutions. Thanks to the way that its stat points are distributed, however, it's up there with the very best. Together with Mega Aerodactyl, it is tied for the title of fastest gen 1 Mega Evolution and its 175 special attack stat is surpassed only by Mega Mewtwo Y. This all bodes incredibly well for this oft-underrated Pokemon, as many of the best psychic-type moves are classed as special attacks. Its trace ability can be a bit hit and miss depending on the Pokemon it's up against, but there are definitely times when it too can really turn the tide in battle.

2 Mega Mewtwo X

Mega Mewtwo X (Pokemon)

For those hoping to utilize Mega Mewtwo X's status as a psychic and fighting-type Pokemon, its 190 physical attack stat is perfect. For everybody else, however, the extra stat points would perhaps be better distributed elsewhere. That's not to say that it isn't a competent special attacker, but its Y variant is a lot more adept in this regard and is also a little faster. A decent ability might have been enough to shift the balance, but, sadly, like Mega Mewtwo X itself, Steadfast is very situational.

1 Mega Mewtwo Y

Mega Mewtwo Y (Pokemon)

Together with its X variant and Mega Rayquaza, Mega Mewtwo Y has the joint highest base stat total in the series with a staggering 780 combined points. A considerable amount of these have been designated to the special attack category, allowing the Pokemon to really make the most of the many devastating psychic type moves in its learnset. Mega Mewtwo Y is no slouch either, with its speed stat coming in at an impressive 140. Once again, its Insomnia ability is a bit of a letdown, although its high speed and attack stats more than make up for this.

NEXT: Pokemon: Every Gen III Mega Evolution, Ranked