<p>I believe that the key difference here is the definition differences between the game mechanic, to anime logic.</p>
<p>What is quoted from bulbapedia, is surely game wise canon mechanic, as wild Pokemon cannot Mega Evolve since mechanically there's need both key stone and mega stone. Anime wise though, while most Pokemon sure does need a trainer with key stone, there's seems to be exceptions the breaks the game logic.</p>
<p>Its not the first time the anime does that really, there's always so many mechanics in the game that the anime seems to ignore or change. (for example, Pikachu were able to beat Broke's Onix in the first series. Onix is ground type and immune to electric, game wise Pikachu cannot beat Onix. Anime wise, break the gym to get Onix wet, and electric is somehow damaging him.)</p>

CC BY-SA 4.0
2024-12-26T16:08:06.010Z
Here is another instance where game canon and anime canon differ like this: [Why hasn't Team Rocket's Meowth evolved?](https://anime.stackexchange.com/a/56498/20275)
Wondercricket
CC BY-SA 4.0
2024-12-25T02:39:19.000Z
2024-12-25T02:39:19.000Z
USerNAme
<p>According to <a href="http://bulbapedia.bulbagarden.net/wiki/Mega_Evolution" rel="nofollow">Bulbapedia</a>: </p>

<blockquote>
  <p>In order to Mega Evolve, most Pokemon must be holding their
  appropriate Mega Stone and the Trainer must have a Key Stone. Only
  Rayquaza does not need a Mega Stone to Mega Evolve; instead, it must
  know the move Dragon Ascent.</p>
</blockquote>

<p>In the Pokemon XY anime, at the end of the first thirty or so episodes there is a short clip introducing all the of mega evolutions. Most of them are seen to be wild and mega evolve as they feel.</p>

<p>If they had a trainer but the anime didn't show it, fair enough. However, what about Mewtwo Y in the 16th movie, and Latias and Latios in the 18th movie, they definitely did not have trainers.</p>

<p>So how do they Mega Evolve by themselves?</p>

CC BY-SA 3.0
2016-09-16T09:48:25.010Z
Actually, I dont even remember seeing mewtwo's stone(any of them) during the movie it(she?) megaevolves.
thePiGrepper
<pokemon>
How do Pokemon Mega Evolve by themselves?
# How do Pokemon Mega Evolve by themselves?
Posted by: username_0 on 2016-09-15
According to [Bulbapedia](http://bulbapedia.bulbagarden.net/wiki/Mega_Evolution):

> In order to Mega Evolve, most Pokemon must be holding their
> appropriate Mega Stone and the Trainer must have a Key Stone. Only
> Rayquaza does not need a Mega Stone to Mega Evolve; instead, it must
> know the move Dragon Ascent.

In the Pokemon XY anime, at the end of the first thirty or so episodes there is a short clip introducing all the of mega evolutions. Most of them are seen to be wild and mega evolve as they feel.

If they had a trainer but the anime didn't show it, fair enough. However, what about Mewtwo Y in the 16th movie, and Latias and Latios in the 18th movie, they definitely did not have trainers.

So how do they Mega Evolve by themselves?
**Tags:** pokemon
> **Comments:**
> **username_1**: Actually, I dont even remember seeing mewtwo's stone(any of them) during the movie it(she?) megaevolves.  
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## 1 answers
### Answer by username_2 on 2024-12-25. Score: 1
I believe that the key difference here is the definition differences between the game mechanic, to anime logic.

What is quoted from bulbapedia, is surely game wise canon mechanic, as wild Pokemon cannot Mega Evolve since mechanically there's need both key stone and mega stone. Anime wise though, while most Pokemon sure does need a trainer with key stone, there's seems to be exceptions the breaks the game logic.

Its not the first time the anime does that really, there's always so many mechanics in the game that the anime seems to ignore or change. (for example, Pikachu were able to beat Broke's Onix in the first series. Onix is ground type and immune to electric, game wise Pikachu cannot beat Onix. Anime wise, break the gym to get Onix wet, and electric is somehow damaging him.)
> **Comments:**
> **username_3** (2024-12-26): Here is another instance where game canon and anime canon differ like this: [Why hasn't Team Rocket's Meowth evolved?](https://anime.stackexchange.com/a/56498/20275)  
---
