User blog comment:RevengerSword15/Beginner Advice?/@comment-28173866-20160807001317/@comment-28173866-20160807094129

I didn't mean every single card ever shown in the anime, just the signature cards.

Those are normally stronger/cheaper(gauge wise) then compareable cards and get tons of custom-made support, making it difficult for others to compete with them. Plus, because of that specific support, most of those decks look quite the same and are basically just rebuilds of the respective characters deck with slight changes. Because of that, no self-respecting player uses them.