What is a booster box
The value of X is determined only once, at the time Rowan, Scion of War's activated ability resolves
It fuels itself incredibly well since drawing extra cards lets you see extra lands that let you draw extra cards that let you see extra lands its a never-ending value train
Masters sets and supplemental sets like Modern Horizons, Battlebond, or Conspiracy also do not count within Pioneer, as is expected
For eight mana, Archetype of Endurance grants all your creatures, including itself, hexproof, but more importantly, it strips hexproof from your opponents and prevents them from gaining hexproof as long as it's in play
Charizard & Braixen-GX (Cosmic Eclipse #22) Here is another Tag Team GX card, though one that features two pokemon from Fire-type starter evolution lines