While the front side is good enough to see play on its own, the fact that it only has four defense counters makes it relatively easy to flip (a single Sheoldred, the Apocalypse attack gets the job done), and the backside offers a very powerful creature that can defeat a battle or kill a planeswalker each turn while potentially generating card advantage as well
Strangely, it seems like the Kamigawa Ukiyo-e lands are also affected, with their mana symbols and Japanese text mysteriously absent
On top of that, your opponent has an even better deck, using a1-30-lilligant Leaf Supply to attach Energy on a1-4-venusaur-ex as they get him ready to carry the game
Double-sleeving is where you put your cards in an inner sleeve before sliding them into the outer sleeve for an extra layer of protection against dirt, moisture and other hazards
Let me know your thoughts in the comments or over in the official Draftsim Discord