Not really. Rayquaza* discards 4 energy to do 100 damage to each of your opponents EXs. There are several reasons I do not lke this attack:
The only way to power it up is by blowing up Electrode-ex. So you have to give up 2 prizes to even use it to attack.
Most EXs have over 100HP, so unless your opponent has multiple damaged EXs in play, the attack will only net you 2 prizes.
It is useless against decks that don't play EXs.
you can only use the attack once per game.
So that's why I don't like Rayquaza* in ZRE.