basic latios pokemon card LP! you may attach a Psychic Energy card from your hand to 1 of your Latias Latios 194/264 - SWSH08 Fusion

Am a little worried that the white deck will become pauper white weenies or a weaker soul sisters/tokens deck both of which might be too much for the other decks to handle

It's about shuffling up your strong and fully optimized deck, whatever it may be, and seeing how it fares

For a single metal Energy, you can use Zacian's Battle Legion attack that does 20 damage and ten more damage for each of your Benched Pokemon while not being affected by Weakness or any effects of your Opponent's Active Pokemon

Just watch out for pricing over MSRP, as we Pokmon trainers are in a weird spot right now, so don't pay more than what you have to, or consider buying single cards instead of gambling on overpriced ETBs