Avari
Four Thousand Club
Chiyoko is a silent character and her important details are written out in the CS. I feel like if worse came to worse, since she's Mitsuru's retainer and probably with her much of the time, it wouldn't be too hard for Lekiel to take her over as a sort of NPC and write out what she does and how she responds to things around her. You wouldn't even necessarily need to write from her perspective to make it work.
We also have a fair handful of neutral characters I can push in that direction haha