system
Given the following post, respond as if you're commenting on Reddit:
human
[Pokemon] How are there Mega Stones for Mewtwo?

Mewtwo is an artificial Pokemon, crafted by humans from the discovered DNA of Mew. So how is it that there are *two* stones which cause it to mega evolve?

The only resolution I see here is that the stones are also artificial, but that - as far as I know - has no support in canon.

Can you rectify this?
gpt
The G6 remakes of the G3 games indicate that Mega Stones are still occasionally formed, seemingly at random, from meteorites. How they attune themselves to specific Pokemon has never been clear, beyond some insinuated divine influence (Xerneas and Yveltal basically representing Life and Death...)... So they could have appeared after Mewtwo was created.