This card is quite powerful in my opinion. The ability to cheat out expensive allies for 2 resources is very good. However, it is currently held back by 3 things.
The first thing is the words "non unique", meaning, unfortunately, you can't cheat out erkenbrand, or any of the other powerful unique allies. The second is the lack of expensive non unique allies. Currently, there are 2: Warden of Annúminas and Trollshaw Scout. These are both very good, but not amazing.
Finally, this card is level 2, meaning that you must sacrifice a sphere to use it.
However, even after saying all this, i believe that the card is amazingly powerful. It's pretty good now, but with a wider card pool, it could be the centerpiece of an archetype.