There were strong arguments for letting Sasuke go given he was attempting to break free of the genjutsu now, and so clearly whatever he was seeing was unacceptable. However, as an Uchiha, he should be more than capable of breaking free no matter how hard she tried to keep him there. Even if she were to exploit sharingan specific weaknesses to keep him under -- and she wouldn't, because she valued her freedom -- someone without one would always be at a disadvantage when facing an Uchiha that did have one. Uchiha were born with genjutsu ingrained in their chakra networks, she'd only learned to manipulate genjutsu.
Thus, she felt no guilt in fighting back against his attempts to break it. This was, after all, also genjutsu training. She reacted immediately to the concentrated burst, bending and adjusting her chakra to ride out his flare of chakra. For the moment, she also bent the rules on not using sharingan specific disguises. Hiding her chakra threads by merging with his and using his as camouflage wasn't exactly going to compromise Shisui...She could simply be innately talented.
...But just to be certain he was too distracted to notice, once his initial attempt to break free passed, she countered by over-stimulating his fear center. It carried the risk of making the genjutsu more disjointed and nightmarish than a cohesive scenario, but like a nightmare it would hopefully confuse and scatter his thoughts badly enough that he wouldn't think about that.
She could ease it back to a real world level genjutsu once his focus was broken. An Uchiha was much too well trained for that to work as a subliminal command not to try to escape again, but it should do well to keep him from asking how she'd hidden (or noticing where she failed) her chakra amongst his.
no subject
Thus, she felt no guilt in fighting back against his attempts to break it. This was, after all, also genjutsu training. She reacted immediately to the concentrated burst, bending and adjusting her chakra to ride out his flare of chakra. For the moment, she also bent the rules on not using sharingan specific disguises. Hiding her chakra threads by merging with his and using his as camouflage wasn't exactly going to compromise Shisui...She could simply be innately talented.
...But just to be certain he was too distracted to notice, once his initial attempt to break free passed, she countered by over-stimulating his fear center. It carried the risk of making the genjutsu more disjointed and nightmarish than a cohesive scenario, but like a nightmare it would hopefully confuse and scatter his thoughts badly enough that he wouldn't think about that.
She could ease it back to a real world level genjutsu once his focus was broken. An Uchiha was much too well trained for that to work as a subliminal command not to try to escape again, but it should do well to keep him from asking how she'd hidden (or noticing where she failed) her chakra amongst his.