An Extra Monster Zone is not a part of either player's field until they Summon a monster to the Extra Monster Zone, meaning they are shared between the players
Slaughter Games is pretty devastating, and the new Lobotomy-Twist, Reap Intellect, looks pretty good, too
(If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.) When Gyruda enters, each player mills four cards
Amazon has it sitting at $47.68, but TCGPlayer is selling the same bundle for just $35.99
Use Drifloon, Scream Tail, and even Gardevoir ex itself to take knockouts as needed
When this is your plan, you should try to keep Aether Vial on two so that you can put Selfless Spirit back on to the battlefield immediately in case of Reflector Mage