For Mew EX's "Versatile" Ability, do I need to have the same energy types as the attack I'm copying, or will any type of energy work as long as I have the correct number of energies?

You must meet the energy requirements as to both type and number for the attack Mew EX is copying. So if the attack requires two Water energy, you will need to have at least two Water energy attached to Mew EX.

Relevant cards