Persephone Leigh sounds really nice. I'm not sure how one-syllable MNs would go though - the syllables of each name would then be 4-1-1. It sounds choppy to say
Persephone Rose [last name]. Almost as if MN and SN sound like one hyphenated name.
I'm glad you like
Persephone. :) At first we thought it was too weird, but we really do love it. And I just figured, it's the sort of name where I'd be thrilled if I met somebody who had it.