Thoughts: Duskmantle Seer brings back the anticipated Dark Confidant ability to the new Ravnica block. Duskmantle Seer has some immediate disadvantages compared to Dark Confidant—most notably, it allows your opponent to draw cards, and it costs four mana instead of two. On the flip side—your opponent draws their extra card on your turn (so unless it's an instant or a card with flash, they can't play it immediately), that card draw costs them life, and Duskmantle Seer is a 4/4 flyer for only four mana. My thoughts are that this is one of those “benefits both players” cards that will end up being extremely good because of the timing of the draw for your opponent. I think that this is the card spoiled in the set so far that has the most room to rise in price; it's mythic, it beats, and it has an extremely powerful effect.

Thoughts: Bulk rare. I'll at least point out that unlike a lot of other cards of this type (Pandemonium comes to mind), the effect isn't symmetrical.

Thoughts: There are good Ball Lightning variants and bad Ball Lightning variants. I put this one in the good pile for the sole reason that Spark Trooper goes a long way to enabling a viable battalion strategy in Standard. The lifelink is a nice bonus, but the real value is getting a Ball Lightning for a deck that wants a Ball Lightning-type card. If battalion decks take off, this has room to hit the $5-$6 range, and quickly.

Thoughts: Cards that have an unpredictable effect like this need to be really good to hold value—if not, they end up in the bulk bins quickly. Is Mind's Desire for one worth four mana? Is it worth it if you get to recast it until you hit a nonland spell? I think that this is not playable in Constructed. For every game you flip Ulamog or Emrakul, you're going to have ten games where you flip Noble Hierarch, Seething Song, or some other piece of your deck that isn't worth four mana to cast.