Sphinx of Jwar Isle and Jace

[m8x115]

The Sphinx allows me to look at the top card of my library (at any time). I just wanted to check, am I able to Brainstorm with Jace and look at the top card of my library before putting the 2 cards back on top?

[AshleyW]

Yes you can.

the ability says Sphinx you may look at the top card of your library. (You may do this at any time.)

which is the same as playing with the top card of the library revealed to you at all times but only you.

As brainstorm says you draw the cards to your hand instead of treating it as you are looking at the top 3 cards (you have drawn them to your hand as opposed to ponder which is look at the top 3 cards) the physical card on top of your library is actually the new top card, even though you still have to place 2 cards back on top after.

The FAQ entry for the Sphinx, backs me up:

* Essentially, Sphinx of Jwar Isle lets you play with the top card of your library revealed only to you. Knowing what that card is becomes part of the information you have access to, just like you can look at the cards in your hand. You may look at the top card of your library whenever you want, even if you don't have priority. This action doesn't use the stack.

* If the top card of your library changes during the process of casting a spell or activating an ability, you can't look at the new top card until the process of casting the spell or activating the ability ends (all targets are chosen, all costs are paid, and so on).

As the Ability has been activated and paid for it allows you to look at the new top card.

[m8x115]

Thanks very much