Shine42 didn't specify the playstyle for this deck
The spider and Marvel symbols (SPE and MAR) will appear on cards that are legal in eternal formats and for any cards that might be new-name versions of cards (similar to the Godzilla treatments from Ikoria: Lair of Behemoths ) already legal in other formats like Pioneer or Modern
If this card is destroyed and sent to the GY: Target 1 monster on the field
So long as The Ur-Dragon is in either one of these zones, your other Dragon spells cost one less generic mana to cast
I remember the best part of being a kid was pulling hits myself and organizing my collection
That shuts down Treasure tokens, Clue tokens, Food, Blood tokens, and many more, not just as utility, but as combo pieces