Somehow, even in a 100-card singleton format, theres never enough room for all the cool spells you want to include, plus the necessary lands to make the deck work
"An Interview with Atsushi Nagashima About New Tag Team Pokmon-GX"
Even within the rules of fan-art I listed above: people buying it know theyre buying a proxy, a replicated card (at least, assuming its not someone trying to hock a proxy off as being authentic) the fact that it does use authentic artwork is tricky, and maybe the most grey of greys involved proxies dont interfere with the rights-holders from selling cards because, well, the rights-holders dont get ANY money from the secondary market to begin with
With Duskmourn , the most expensive cards in the set are called "fracture foils" and they're only available on the Japanese Showcase versions of certain rares
Three mana to have your lands tap for any mana is a decent rate, and W&R's -2 is top notch
Sarkhan Unbroken provides a ton of advantage for players when he comes into play, with his first ability both drawing you a card and adding one mana of any color to your mana pool