If the controller of Unyielding Gatekeeper's last ability controlled the target permanent at the time the ability began to resolve, the permanent will return to the battlefield tapped under that player's control, regardless of who its owner is
After he dies, if you need the guy back, sacrifice the Food and bring him back for free, and that doesn't count as your spell for the turn
Besides the Ability, Mew EX has one move called Replace which requires one psychic energy card and allows you to move any of the energy cards you have attached to any of your Pokemon in any way you like
This standard EX version shows Mega Charizard in attack stance
It shows there's still a good amount of life left with it and it wouldn't surprise me if we see more in the future, meaning that you may find even more ways to rework your list in the future
As the game progresses, your chances to freely attack diminish since most of the creatures in this deck cant push through blockers