KH, I just read your last reviews on Sylph. I'll say the same thing I would say about Shelob: this milieu is more than just setting. Leave her alone. Whether this develops fully as a Milieu Story or not, Sylph is as important to the story as the University President is to yours. Meaning you could put something else in her place, but the something else has to fit the place.
The University President couldn't be an old stoner whose conversation is interrupted by recurring fugue states. (Or maybe he could be, and maybe you'd like to take up the challenge, but it will be a distraction in the story.) So too Zylph must be a critter of the wierd. She doesn't have to be an ant colony. She could be a sentient slime mold or an eight-foot porcupine with blinding speed, but she has to crepulate us or horripilate us, or both.
Postscript: The Big Story Message is If these are our friends, what will we meet as enemies?