how to authenticate mtg cards a double-sided Magic: the Gathering card? I made this simple visual

Ashnods Altar is a three mana Artifact that allows you to sacrifice a creature to gain two colorless mana

So, what is the penultimate pick, the weaker of the two

Prismari Artistry

These cards appear only once in every 144 booster packs, starting with the Zendikar Expeditions series

Ill be adding this to my Glacian, Powerstone Engineer + Toggo, Goblin Weaponsmith deck as a way to punch through damage, and I can see other decks like Emry, Lurker of the Loch following suit over time

Don't you hate it when you cast Cultivate and only have one basic land left in your library because your two-color deck only had six or eight basics total