Schopenhauer is referring to the selfsame thing when he gives his major work the title The World [not man] as Will and Representation. Nietzsche is thinking the selfsame thing when he acknowledges the primal Being of beings as will to power.
That everywhere on all sides the Being of beings appears consistently as will does not derive from views on being which a few philosophers furnished for themselves. No amount of erudition will ever uncover what it means that Being appears as will. What it means can only be asked in thinking; as what is to be thought, it can only be celebrated as worth asking about; as something we are mindful of, it can only be kept in mind.
In modern metaphysics, there for the first time expressly and explicitly, the Being of beings appears as will. Man is man insofar as he comports himself to beings by way of thought. In this way he is held in Being. Man's thinking must also correspond in its essence to that toward which it comports itself, to wit, the Being of beings as will.
Now, Nietzsche tells us that prior thinking has been determined by the spirit of revenge. Precisely how is Nietzsche thinking the essence of revenge, assuming that he is thinking it metaphysically?
In the second part of Thus Spoke Zarathustra, in the episode we have already mentioned, "On Redemption," Nietzsche has Zarathustra say: "This, yes, this alone is revenge itself: the will's ill will toward time and its 'It was.'"
That an essential definition of revenge emphasizes revulsion and defiance, and thus points to revenge as ill will, corresponds to our characterization of it as a peculiar sort of persecution. Yet Nietzsche does not merely say that revenge is revulsion. The same could be said of hatred. Nietzsche says that revenge is the will's ill will. But will signifies the Being of beings as a whole, and not simply human willing. By virtue of the characterization of revenge as "the will's ill will," the defiant persecution of revenge persists primarily in relationship to the Being of beings. It becomes apparent that this is the case when we heed what it is on which revenge's ill will turns: revenge is "the will's ill will against time and its 'It was.'"