I'm most concerned with the colored generic tribal cards, which are pretty much guaranteed to be sideboarded most of the time
you can do much better for actual mana doubling
You get 15 Prismatic Evolutions booster packs, a full-art foil Eevee ex promo card, a fuzzy Eevee deck box that collectors go crazy for, a playmat featuring all the Eeveelutions, and 65 card sleeves with matching artwork
Your top priorities should be "OP04-096 Corrida Coliseum" and "OP04-082 Kyros"
As a more outside of the box strategy, Yuna appeared as a four-of in a Naya Enchantments build that loots away the Overlords with Fear of Missing Out
WOTC and MTG have taken the source material to heart with the new set and have introduced the main characters of Avatar: The Last Airbender as their original portrayals, but like the animated series, these characters will all undergo trials and tribulations, receiving transformed (and older) appearances and receiving ability upgrades that coincide with their journey in the series