There's one in the bottom of Savin's design doc for Kara Quest 2 about what happens if Shade simply lets you go instead of making you fight her.
Her encounter during KaraQuest 2 is temporarily disabled when she is technically supposed to be on Uveto. I had added that check because there was a bug report or mentioning of that somewhere and I thought it would be best to fix that consistency issue. Her bar encounter should still be possible after the quest though, which was Savin's intent. This should be more obvious when Uveto is in though. Shade should only appear in KQ2 if she is canonically on Myrellion, so it is only possible to see her if she hasn't mentioned going off to Uveto.
If this is not how it is supposed to be, I can try changing it back.