The foil promo card players receive will be either Eevee EX, Vaporeon EX, Jolteon EX, Flareon EX, Espeon EX, Umbreon EX, Leafeon EX, Glaceon EX, or Sylveon EX
Lowers the Barrier to Entry for New Players: A smaller, more recent card pool makes it easier and less expensive for new players to get into competitive play, as they dont need to acquire a vast collection of older, potentially hard-to-find cards
It taps for mana like normal, but you can also load it with a charge counter and then unleash a the stored-up mana on your next main phase
As for The Ozolith, it stores up our +1/+1 counters as our creatures die and then allows us to dump them all onto a creature at the beginning of combat to build a massive threat
So which one is right for you
Indeed, your only issue in getting this deck going will likely be how reliably you can evolve one or more Barbaracles on your field