I freely confess to loving angst, particularly Visored angst. Though in this case I've given them good reason for it. Hence why I've updated so insanely often. I'm considering writing alternate endings: one good, one canon-like, one just plain different, and one very bad.
Three days later
Unohana Retsu prides herself on her knowledge of the healing arts. She almost single-handedly brought the techniques to the point they are today, working tirelessly to mend broken bones and calm raging infections. There are still illnesses she cannot cure, still wounds that the Fourth Division's long-standing captain cannot heal. But there will always be such things, and Unohana must keep striving to do better and heal what she can.
Her extensive mastery of healing Kido is exactly why the black-braided woman is utterly confused by the illness of eight of her coworkers. Their symptoms don't match up with any disease she knows of, and the medicines she's had her division members slip into their food didn't work. Now that Unohana suspects that despite what they say, they really can't keep any food down, she can't do that, but still. The fact that she can tell that they're trying to downplay and cover up their symptoms is even more bizarre, coupled with their strong avoidance of the Fourth Division.
No one disobeys Unohana Retsu. It simply isn't done, just like wearing carp streamers on the feet instead of shoes isn't done. But that's exactly what the eight are doing. Where they get that audacity is utterly beyond her.
The Fourth Division's captain sits at her desk in her office, writing an outline of the visible symptoms for the millionth time in the hope that something will jump out to her this time and she'll magically find the answer. It's the only thing she can do, all other options having been exhausted. All other legal and socially acceptable options, anyway.
Vomiting, severe weight loss, coughing, hand tremors, stiffness and limited range of motion, and overall weakness. It could match to several other illnesses, but none of the other symptoms of those diseases are present and the secret medication she slipped in for those illnesses didn't make a dent. None of this makes sense, and the black-braided woman frowns slightly at the paper, which shreds itself into many pieces with the tiniest exertion of her spirit power on it.
It could be a new illness, she realizes with a bit of horror. One previously unknown, maybe even a sickness of the soul itself. Hollows have a wide range of abilities, and it is possible that one could have the power to induce illness. But no, that doesn't make much sense, because Unohana knows how to flush Hollow reiatsu out of wounds to keep from such infections. In any event, her powers would be more than enough to break down any resistance of its power.
Speaking of Hollow reiatsu, there was very, very faint traces of it in Kotsubaki Jin'emon's nasty wound a short while back. Traces that spoke of very high power levels, like the strong tastes or smells of spices even in small amounts. That was a complete enigma, one she hasn't been able to puzzle out and hasn't had the time to with the number of people being hurt by increased Hollow incursions.
For once, Unohana Retsu is completely powerless in a matter of medicine. She can't help them because she doesn't know what disease they have, and she doesn't know what disease the eight have because they're refusing treatment and undoubtedly concealing other symptoms. Even in her days as the first Kenpachi, no wound was beyond her power to fix. The black-braided captain knows her sword well, and it was almost child's play to mend the tears of flesh and shattered bones that Minazuki caused. This isn't familiar, it isn't normal, it isn't natural. It simply isn't right for the Fourth Division's captain not to know about an aspect of medicine.
Unohana rises from her kneeling position at her desk and makes her way through her division, offering words of encouragement and helpful critique as she goes, steadying a hand here and reminding a Shinigami of the proper procedure there. When she leaves, the former Kenpachi is no less deeply troubled.
A god of death with power over the workings of life should not have to stand by helpless as her allies are dying.
Well, Leviathan, you got your wish! It was such a good idea that I couldn't help using it!