Pachirisu ex (2 Shiny Stars rarity) is the #A4-236 card from the Wisdom of Sea and Sky set in Pokmon TCG Pocket
Obviously enough, The First Doctor is the one who started it all
Officially, Special Art Rare cards from Sword & Shield series called Galarian Gallery Ultra Rares, and they feature either a white star or the GGU label as their rarity symbol
They're equally satisfied by an artifact you sacrificed to pay a cost, a creature you controlled that was destroyed by Murder, or an enchantment you returned to your hand with Leave in the Dust
Q: What happens if not enough Dragon Duel eligible Duelists register for the Dragon Duel
Your other option is also excellent, which is to fight with one of your opponent's creatures, which is one the 7/7 monsters will almost always win