1 foil promo card featuring Cinderace ex
No big deal
This design not only reflects its elemental typing but also symbolizes the merging of technology and nature, a recurring theme in the Unova region

A comprehensive breakdown can be found here: The Different Rarity Symbols in Pokemon Card Sets Explained , but a brief summary: Common Japan designation: C image429599 44.3 KB image250250 1.16 KB Uncommon Japan designation: U image429599 46.4 KB image250250 726 Bytes Rare (Holo) Japan designation: R image660920 111 KB image250250 1.34 KB Double Rare (standard ex) Japan designation: RR image429599 58.4 KB image250250 2.3 KB Ultra Rare (generic full arts) Japan designation: SR (super rare) image430599 51.9 KB image250250 2.3 KB Hyper Rare (gold cards) Japan designation: UR (ultra rare) image660920 137 KB image250250 2.85 KB As for before Scarlet and Violet, the above is basically the same, except english did not have the updated star system for cards beyond ultra rares Note on Rainbow Rares The Japan HR or Hyper Rare rarity referred mostly to Rainbow cards

Karador, Ghost Chieftain needs to rapidly stock up its graveyard, and aside from assigning chump blockers, the Magic deck can fuel its graveyard with self-mill effects ranging from Skull Prophet and Nyx Weaver to dredge creatures like Stinkweed Imp and Golgari Grave-Troll
Well, if you have foil copies then someone out there is looking for them, and finding stuff like this in collections is always a treat