i dont know beat the game i gues
You can't catch Mewtwo in-game in Pokemon Diamond.
Mew and Mewtwo are not found anywhere in the Sinnoh region.
You can't you can only get mew two but that's just me.
You cannot catch Mew in "Pokémon Ruby."or you can get mew-two in fire red or leaf green.
Mt.Moon
I don't think you can catch MEW without a action replay. But you can catch MEW2 in Pokemon Fire Red or Leaf Green. You CAN'T cach mew without an action replay, but you can trade mew-two from the other games to the newer ones
All Pokemon list require a trade or you to import via Pal Park. As none are wild in Pokemon Diamond.
The Cerulean Cave
YOU JUST COItinue what your doing
sadly,no
You catch Mew-Two
you can't Mew and Mewtwo are two completely different pokemon. Mewtwo is accually a clone of the original Mew. So... no, you can't evolve Mew into Mewtwo.