All of sudden wondering what Nietzsche thought of Schopenhauer, I looked into the index of Will to Power for his remarks on same. I found that, among other things, while he credited Schopenhauer for identifying “will” with Kant’s “things in themselves” he faulted him for failing to “deify” the will [1005]. (For Schopenhauer, will-lessness was the preferred state. For Nietzsche the kind of will was quite important.) Elsewhere [WTP 685] Nietzsche interestingly distinguishes between will and desire:

“Willing” is not “desiring”, striving, demanding: it is distinguished from these by the affect of commanding. There is no such thing as “willing,” but only a willing something […] The state of tension by virtue of which a force seeks to discharge itself — is not an example of “willing”.