Mega Evolution

Mega Evolution is an additional, temporal evolution form of specific Pokémon that reached their final evolution stage.

Mega Pokémon are more powerful forms of Pokémon with their attacks boosted as well as their Combat Power. Moreover, Mega Pokémon will boost the attack power of all other Pokémon when battling in Raid Battles. Pokémon with the same type as the Mega Evolved Pokémon will receive an even greater attack boost. HP of Mega Evolved Pokémon is the same as its standard form. Certain Pokémon may also change their types after Mega Evolved.

Similarly to the main series games, Mega Evolution is temporary, however in Pokémon GO it is a temporal change of form that occurs in Trainer's Pokémon collection instead of a single battle.

Mega Evolved Pokémon can be assigned as a Buddy Pokémon and used to battle in raids and Gyms or against another Trainers and Team GO Rocket members. However, they cannot be deployed to defend Gyms, traded nor used in GO Battle League matches. Pokémon cannot be Powered Up during Mega Evoltion.

Mega Evolving a Pokémon
In order to Mega Evolve a Pokémon, Trainer needs Mega Energy of specific Pokémon.

Pokémon will remain in their Mega form for 4 hours. Only one of Trainer's Pokémon can be Mega Evolved at any particular time. If another Pokémon is Mega Evolved, the previous Mega Evolved Pokémon will revert to standard form.

Each Mega Evolved Pokémon for first time is registered to the Mega Pokédex.

Clone and Shadow Pokémon cannot be Mega Evolved.

Mega Energy
Mega Energy is a consumable resource that is similar to Pokémon Candy, as each Pokémon species has specific Mega Energy. While a Pokémon is Mega Evolved, its Mega Energy will deplete over time.

Mega Energy for a particular species can be received by battling that specific Pokémon in Mega Raids – another tier of Raid Battle or completing Research tasks.

Mega Evolving a Pokémon for the first time costs a significant amount of Mega Energy, Mega Evolving that one Pokémon subsequent times will cost less energy. Pokémon like Charizard have two Mega forms, both of them require to be unlocked at full cost first.

List of Mega Evolved Pokémon


The following Mega Evolved forms are available in game assets.

The following Pokémon are capable of Mega Evolve in the main game series.

Reception
Despite being highly-anticipated by the community, Mega Evolution caused a public backlash regarding its implementation. A Reddit post criticizing Mega Evolution received over 8000 upvotes and 100 rewards within the launch day. Many have pointed out the duration of Mega Evolution is not worth the Raid Passes spent on collecting Mega Energy. The difficulty of Mega Evolving one's desired species is also in concern due to specific Mega Energy and the rarity of Mega Raid Battles.

Since there is specific Mega Raid Bosses pool, there would be no way to Mega Evolve any Pokémon that has its Mega Evolved form released but is no longer available in Mega Raids. For example, once all Beedrill Mega Energy from A Mega Discovery is used, there is no possibility to continue on Mega Evolving Beedrill for a longer time period.

Competitive players have expressed their worries of Mega Evolution greatly enlarging the gap between free players and "whales". Mega Evolving Pokémon daily takes 1 to 2 Raid Passes to gather Mega Energy, which is impossible to catch up for free players.

Outside of Mega Evolution, replacing team contribution with speed bonus does harm to Premier Balls in Tier 5 Raid Bosses. It is impossible to defeat certain Legendary Pokémon in a short time, even for large group, while having more Trainers mean lowering the damage bonus.

Niantic has made a statement "We are actively listening to your feedback and look forward to sharing more about how this feature will grow in the future." in the Pokémon GO official Twitter page.

Trivia

 * In original game series, Mega Evolution was an additional evolution that allowed Pokémon to transform into stronger form of their final evolution stage during battle.
 * Mega Evolution was first mentioned in the Pokémon Presents on June, 2020. It would be released in Fall 2020.
 * It was officially released on August, 2020.
 * Mega Lucario and Mega Mewtwo Y along with balloon of Mega Charizard X were featured in the key artwork for 4th Anniversary.