In order to get the 151st Pokemon Mew, you’ll need to make sure that the account you’re playing Pokemon Brilliant Diamond and Shining Pear on has saved data from Pokemon Let’s Go Pikachu or Pokemon Let’s go Eevee. However, unlike those games, you do not have to have owned the Poke Ball Plus in order to obtain the legendary. All you need to do is play the game long enough that you can save it, meaning if your friend has a copy, you can borrow it, play for a few minutes and then save, earning yourself a Mew.
In order to claim Mew, head to Floaroma Town, which is one of the first you’ll travel to on your journey. In a field filled with flowers, there is an old man and an old woman. Speak to the woman and she’ll comment that she has a Pokemon she wishes you to take care of. That Pokemon is Mew. That’s all you need to do in order to have one of the most versatile Pokemon in the whole series on your team.
In order to claim Mew, head to Floaroma Town, which is one of the first you’ll travel to on your journey. In a field filled with flowers, there is an old man and an old woman. Speak to the woman and she’ll comment that she has a Pokemon she wishes you to take care of. That Pokemon is Mew. That’s all you need to do in order to have one of the most versatile Pokemon in the whole series on your team.