Revival is a tome found in Adventure Mode of Diablo III. It is dropped by Zoltun Kulle when he first talks to the Nephalem about Kanai's Cube, starting the respective quest.
It reads as follows:
The nephalem, that fool, actually killed me. Of course this was not my first time stepping through that door, and I imagine it won't be my last. Fortunately, I am well prepared. Some would say that animating a constructed body with preserved memories is not truly coming back to life. I say those fools don't understand the sheer wonder of being Zoltun Kulle.