The most directly relevant statement he makes is probably
“To those human beings who are of any concern to me I wish suffering,
desolation, sickness, ill-treatment, indignities—I wish that they
should not remain unfamiliar with profound self-contempt, the torture
of self-mistrust, the wretchedness of the vanquished: I have no pity
for them, because I wish them the only thing that can prove today
whether one is worth anything or not—that one endures.” -from The
Will To Power (which it must be noted is a controversial text, as it
was compiled by his sister from notebooks towards supporting the
Nazis)
He also said
“Only great pain, the long, slow pain that takes its time... compels us
to descend to our ultimate depths... I doubt that such pain makes us
"better"; but I know it makes us more profound... In the end, lest
what is most important remain unsaid: from such abysses, from such
severe sickness, one returns newborn, having shed one's skin... with
merrier senses, with a second dangerous innocence in joy, more
childlike and yet a hundred times subtler than one has ever been
before.” -The Gay Science
And
“Out of life’s school of war—what doesn’t kill me, makes me stronger.”
-Twilight of the Idols
I would look to Nietzsche as advocating that being an ‘overgoer’ means risking being a down-goer - to cross the abyss we must relish the hazard, the danger of suffering. Discussed here: Trying to Understand Quote by Nietzsche
I would suggest that is parallel to going ‘beyond good and evil’; that we need to go beyond the dictates of pain and pleasure, towards other higher values goals and motivations. But not by numbing ourselves or ignoring the pain.
Nietzsche rejected limiting our desires in order to limit suffering, and advocated embracing tragedy - that the quality of a story is not defined by how happily it ends, which surely every story teller knows.
“In pain there is as much wisdom as in pleasure: like the latter it is
one of the best self preservatives of a species.” -The Gay Science
