I'm thinking, plot-wise, if Nyx might incur some damage for two reasons.  1. I want Asteria to heal Nyx which may build towards their eventual fusion, and 2. originally, Nyx was supposed to be the 'runt of the litter' among the cogs: considered unwanted and weak, so a low performance would push that particular point of drama.  Of course, do let me know if you don't want Blythe to be as much of a punching bag.