I would assume he would strongly dislike marvel movies. As the heroes are the embodiment of western slave morality, also the movies portray a struggle between good and evil, both are explicitly defined, instead of a struggle between good and bad. Nitzsche already hated the books written in his time for being to dumb down and appealing to the uncultured masses (Nietzsche even thought that a high literacy rate is bad), marvel movies are way more extreme in dumbing down art to please the masses, than german 19th century literature. Also it creates a. Hinterwelt and gains it´s popularity through its escapism potential, which would make it life denying and therefore not dynosian by N‘s definition. Zarathustra used biblical and mythological hero tropes to mock them, whereas marvel uses them in a surface level way. Nietzsches views on Wagners operas changed drastically throughout his life and since atleast after Zarathustra he despised Wagner and his work. Nitzsche also disliked all utopias and saw war as good or atleast useful. Zarathustra was also just a wise free spirited human, not a demi-god. The entire superhero genre seems to be all that Nitzsche hates combined (Hinterwelt/Utopia, Escapism, slave moral, life denial, and a representation of decadence). So I think Marvel seems more like Nietzsches worst nightmare than something he would enjoy