When i first read WoR i assumed that when Listeners whet into stormform they all became like Eshonai. That they lost part of they minds, and something else took over. But looking back on it a lot of Eshonai's action in stormform don't add up with that assumption. If every Listener in stormform fell under the control of Odium then it seams like the first thing stormform Eshonai would do would be to gather all the smartest, freest thinking Listeners and get them into stormform. As a way to neutralize any opposition. Instead she dose the opposite. She seams afraid of anyone too smart going into stormform. She picks out people who take orders easily, and don't think for themselves as the first ones to take on stormform. At first i thought she didn't want strong willed people transforming because they might be able to brake out of being controlled. But then Eshonai super strong willed herself and that doesn't stop her from being controlled. I'm guessing that stormform, and the other 'forms of the gods' make Listeners more pron to hatred, and violence, and open up a doorway for Odium to control them. But that he can only control a few at once. Probably only 9. I think the 9 people Odium is controlling (both Listeners, and humans bonded to voidspren) are spread all over Roshar. And that Eshonai was the only Listener on the Shattered Plains directly under Odium's control.