Fortunately, there are some simple ways to discover the rarity of any Pokmon card, and the system as it stands today can likewise still be fully explained with little issue
Before the release of the base set of Scarlet and Violet, the majority of rare cards had just one black star, regardless of what level of rarity they were One Black Star Weve already shown you this, as you can see from the image above
For decks focusing on Link Summoning, the AI will Link Summon monsters whenever possible using whatever monsters on the field, even if it's summoning the same monster, sometimes spending several minutes summoning and banishing Link monsters
Heck, the first card spoiled for the sheet was Mutavault, which isnt awful, but its hardly a pack-seller either
Forbidden Memories has its own story that doesn't really intersect with the actual plot of Yu-Gi-Oh , but is more of an alternate retelling