For post-rotation change :-
- VIP to Buddy Poffin
- Heavy Ball to Heavy Baton
- Toy Catcher to Prime Catcher/Master Ball
- Metang to New Metang with Ability
Metal Maker - Once during your turn, you may look at the top 4 cards of your deck and attach any number of basic metal energy you find there to your Pokemon in any way you like. Shuffle the other cards and put them to the bottom of your deck.
Zamazenta is a personal preference, I wanted to make it a backup attacker with Sky Seal due to the high amount of Arceus/Giratina/Zeraora/Flying Pika/Goodra/Palkia being played in my local.
I also think of adding Mist Energy/Toedscruel EX to prevent Giratina/Roaring Moon to one-shot the Melmetal because Heavy Baton won't trigger if they get knocked out by effects.
Any opinion please do share it in the comment section.