Entei's design draws inspiration from various mythological creatures, resembling a lion with a regal mane and a fiery aura, which is fitting given its type and majestic presence
Right now, that feels like a very strong recommendation
This Rainbow Energy captures the spirit of that by doing ten damage to the Pokemon you attach it to
GXs are a generally more balanced type of card because rather than immediately play some huge basic card like a Charizard EX, you may have to spend a few turns to get out something like a Solgaleo GX or Alolan Ninetales GX
The rules explicitly point out that getting tabled is not an automatic victory, and the remaining side should play out the remaining turn limit to see how many points they can acquire, particularly in tournament and narrative play (where the exact number of victory points gained matters beyond that one match)
The other half of the deck is primarily made up of Elf synergy cards, though there are a few odd choices thrown in that make the whole deck feel a little disjointed