Ultra-Humanite's brain (or consciousness, at least) is in Terra's body. Does Satanna know this?
Satanna's supposedly out for revenge because Power Girl defeated U-H and put him somewhere Satanna couldn't find him. As we know, he's not there anymore. Well, the albino gorilla body probably still is, but his mind clearly isn't. Not only is she trying to get revenge, it seems to be "kill you" revenge, rather than "make your life miserable" revenge. If she knew U-H was out and about, she probably wouldn't be trying to kill the person he wants to put his brain inside*. U-H seemed pretty angry with her, with the threats of blinding or worse if she didn't give him the code to deactivate the gravity well.
I'm saying "seems" a lot, because there was a phrase that makes me reconsider all of it. In #10, Satanna's Angry Badger Scientist calls the Manhawk attack "Phase Three". It tells me everything thrown at Power Girl in #9 (the elephant and rhino-men, the sonic hammer, the gravity well) was just an opening salvo, and this is the continuation of a larger scheme. If those were really part of an attempt to kill Peej, then it failed and the Manhawks would be more of a "Plan B". It might also explain how Satanna escaped being encased in rock up to her chin as soon as she coughed up the code**.
Granted, if this was some plan for U-H to play at being Terra to learn everything he could about Power Girl, likely to use as some way of getting Peej to do what he wants***, he kind of botched it by being too '90s in his heroing, but he is nuts, and probably couldn't figure any other way to be heroic. I know Angry Badger Scientist said in Power Girl #8 he hadn't located U-H yet, but a) he didn't know U-H was in Terra's body (if he was by then) and b) he did have hundreds of agents looking, so they may have tumbled to that fact. If not, there's nothing that says U-H couldn't have shown up in Terra's body and convinced Satanna to modify her revenge plan to suit his purposes.
It would be funny if Satanna really doesn't know, and in trying to kill Power Girl, ends up screwing up Ultra-Humanite's plans, and the two end up fighting and defeating each other. Or U-H tells Satanna it's him, but in the time that takes, Power Girl comes up with some way to stop them both. Ooh, maybe the Angry Badger Scientist will turn against Satanna because he's worried she'll find him expendable once she has Ultra-Humanite back!
Then Angry Badger Scientist can be a hero! That'll be the best thing ever! Well, not the best thing ever, but a really good thing.
* I'm guessing the brain transfer wouldn't work if Power Girl was dead.
** I guess it's possible the rock formation Terra-Humanite made could crumble with his concentration, but I figured it was more likely it wouldn't go away unless he willed it.
*** You know, "Let me put my brain in your body or I'll strike at all your loved ones" Moo-Ha-Ha stuff.