Can Mew ex's "Genome Hacking" attack copy an opponent's VSTAR attack that has already been used?
Yes, Genome Hacking can copy an opponent's VSTAR attack, even if the opponent has already used up their VSTAR attack for the game. However, if you have already used your own VSTAR Attack you cannot choose to use a VSTAR Power attack with Genome Hacking; you must select a valid attack to use.
Source: TPCi Rules Team (2023-12-14)
Do I have to meet the energy requirements for the attack I choose with Mew ex's "Genome Hacking" attack?
No, you do not have to meet the energy requirements for the attack. However, if the attack says you must do something or the attack does nothing, that part still has to be done.
Source: TPCi Rules Team (2023-09-28)
Can Mew ex's "Genome Hacking" attack use Medicham V's "Yoga Loop" attack to repeatedly get extra turns?
Yes, Genome Hacking on Yoga Loop could work infinitely, if you're able to pull it off!
Source: TPCi Rules Team (2023-09-28)