Mindswipe is a great ending spell, but I would not use it as an early counter spell since there are far better options. I built a shell with the sole purpose of casting it late game.
And I was able to cast it for the win (FTW) against a Villanous Wealth deck.
Here is Mindswipe winning me a game. It is not that consistent and against fast decks it is quite useless... we shall see how it plays when Fate Reforged enters the format.
Update for version 2: I lost to flyers and made a small change. Two Chasm Skulkers out; two Stormchaser Chimeras in. Now the deck is balanced and well thought out. It will take me a while to get good at it because of how many interactions are in it at the same time.
I pulled another awesome Mindswipe casting FTW... so sweet.