Top Nero player SAT made a somewhat early matchup list for Nero in 1.07. Interesting that he thinks the Hime matchup is slightly advantageous.
Disadvantage: CH-Nanaya, CH-Warc
Slight disadvantage: CF-Arc, HF-VAkiha, CH-Ciel, (H-Roa)
Even: F-VSion, C-Mech, Miyako, HF-Kohaku, CH-Wara, CF-Maids, (F-Aoko)
Slight advantage: C-Seifuku, CH-Shiki Tohno, C-Hisui, F-Hime, HF-Sion, F-Kouma, F-Ryougi
Advantage: Satsuki, F-Ries, HF-Len, Akiha, CF-WLen, H-PCiel
He states that H-Roa and F-Aoko are in parentheses because he hasn't played many strong players using those characters in 1.07, so it's a guess.