The will to power:

"Precisely if all views of the world are interpretations, i.e. acts of the will to power, the doctrine of the will to power is at the same time an interpretation and the most fundamental fact, for, in contradistinction to all other interpretations, it is the necessary and sufficient condition of the possibility of any 'categories'."
(Leo Strauss, "Note on the Plan of Nietzsche's Beyond Good and Evil".)

The eternal recurrence:

"In the new wisdom of [Nietzsche's] Zarathustra, the wise man, the spirited knower, is a lover who transforms the beloved [the world as will to power] into something still more beautiful than she is [namely, into the world as eternally recurring will to power], and she is beautiful as she is."
(Laurence Lampert, Nietzsche's Teaching, page 120.)

The Superman:

The Nietzschean Übermensch, a.k.a. the philosopher of the future and the complementary man, is the natural end of man in the sense that he is at the same time 1) man's peak and 2) natural in the sense of "the pure, newly found, newly redeemed nature", which is basically nature according to modern natural science (cf. Beyond Good and Evil aph. 22). He is man's completed state; and he is natural---highly, freely, even terribly natural.