Its an enchantment in either case, but its only a noncreature spell when cast as an aura
I had asked the team for a spell-based mechanic and Aaron sent in ten suggestions
Cycling See more Add To Wishlist Restock Notice Gatherer & Rulings (opens in new tab) NM EX VG G 8 available @ $11.99 Add to Cart 1 2 3 4 5 6 7 8 $9.59 Out of stock
Prophet of Kruphix Price at Release $4 Predicted Price $1-$2 Current Price $4 People have been drooling over this cards potential in a Standard Bant shell, but I dont see that deck ever being too viable
Since Zirda, the Dawnwaker only cares about permanents, it could show up in a deck that is mostly (or exclusively) spells (people have mentioned this as a possibility in Vintage, where some decks incidentally meet Zirda, the Dawnwaker's restriction, although whether or not getting a random 3/3 in hand to start the game is worth a sideboard slot remains to be seen)
You could think of them as either a land that has a payoff if you draw it late, or a spell that you can use as a resource in the early turns