These cards introduced the idea of an Ultra Rare (better than holo) card that could be pulled in the main portion of the set that then had a textured, Full Art version at the end of the set

Thopters Moon Girl and Devil Dinosaur 0.2%inclusion 1 decks 502 decks Top Commanders Breya, Etherium Shaper 28%inclusion 282 decks 999 decks Leonardo da Vinci 17%inclusion 169 decks 999 decks Pia Nalaar, Consul of Revival 9.3%inclusion 93 decks 999 decks Sai, Master Thopterist 7.5%inclusion 75 decks 999 decks Mendicant Core, Guidelight 3.7%inclusion 30 decks 814 decks Urza, Chief Artificer 2.7%inclusion 27 decks 999 decks Ghyrson Starn, Kelermorph 2.4%inclusion 24 decks 999 decks Cayth, Famed Mechanist 2.1%inclusion 21 decks 999 decks Saheeli, Radiant Creator 1.6%inclusion 13 decks 814 decks Brudiclad, Telchor Engineer 1.2%inclusion 12 decks 999 decks Pia Nalaar, Chief Mechanic 1.5%inclusion 12 decks 814 decks Urza, Lord High Artificer 1.1%inclusion 11 decks 999 decks Saheeli, the Gifted 1.1%inclusion 11 decks 999 decks Urza, Lord Protector 0.8%inclusion 8 decks 999 decks Dr
Stew the Coneys
Your grail on the cover
51/102 Koffing
With each individual code given out, the discount would decrease by .01%