Flooding Derpibooru with a bunch of parody cards seems like a bad idea to me, so you can find all cards individually in the Source URL, where they have the name of the cards they were based on in each image description (because I suck at coming up with original cards, so they are all parodies of the Magician Girl archetype and its related cards).

I know 20 cards is very Duel Links-ish and some people are not very cool with that, but slap some duplicates in there and you're all set. Some may be limited/semi-limited, but I'll let you make that decision on your own.