1. Revise Nock's translation (in line with Murray, whom Nock criticizes in his own footnote), to read both genitives together: "Of the supramundane Gods, some create beings..."
2. The option that boccaderlupo gives us upthread.
Either way, hyperkosmiōn is an adjective that requires a noun; we supply that noun—"Gods"—from the previous sentence (and in option 1, it's explicitly there in this sentence, too).
no subject
1. Revise Nock's translation (in line with Murray, whom Nock criticizes in his own footnote), to read both genitives together: "Of the supramundane Gods, some create beings..."
2. The option that
Either way, hyperkosmiōn is an adjective that requires a noun; we supply that noun—"Gods"—from the previous sentence (and in option 1, it's explicitly there in this sentence, too).