+1: Look at the top card of your library. If it's a noncreature, nonland card, you may reveal it and put it into your hand.
−2: When you cast your next instant or sorcery spell from your hand this turn, it gains rebound.
−9: You get an emblem with "Your opponents can't cast noncreature spells."
2/25/2015 When resolving Narset’s first ability, if the top card of your library is a creature or a land card, or if you don’t wish to put it into your hand, it isn’t revealed.
2/25/2015 If a spell that exiles itself as part of its own resolution, such as Volcanic Vision, gains rebound, the ability that lets you cast the spell again won’t be created. The spell will simply be exiled.
So long as the right deck is around (UWR control, Esper control etc) I think she's going to be playable.