You'll make six copies of Cloud, which then go and search for six more Equipment (before being removed due to the legend rule), and repeat the process every single turn
There are a lot of good cards in this set, so I likely missed a few
See the future and cast miracles with Miracle Worker, fill your graveyard and reanimate monsters with Death Toll, cast tricky instants and mysterious face-down cards with Jump Scare!, or control monstrosities and make your opponents pay with Endless Punishment
Instead, this variant is featured in early marketing materials, hence why it is called the "marketing variation" of Ivy Pikachu
Is it due to market demand
I have never gone 42 cards, I am sure my pool would allow for it often enough but I have not seen a reason to