It gives them swampwalk , so if an opponent has a Swamp, you'll be able to attack them without them being able to block your Zombies
That said, there are a few common synergies worth discussing
Mewtwo Ex has an ideal combination of high attack power, speed, and energy consistency
Glassblowers Puzzleknot synergizes with cards that use energy, cards that care about the top of your library, cards that reward you for artifacts, and cards that, when drawn at the right times or in the right combinations, have a disproportionately large impact
This deck hopefully gives you plenty of ways to deal with surprises while still aiming for it's overall goal of being the evil tyrant of the night Nightmare Moon always wanted to be~ Get revenge on those nasty cartoon horses for not appreciating such a deep and caring princess