She might not have a say in the matter though. I doubt Juliette or Charlotte (who has a permission from Olivia to hunt down Kane) care much for what Callista thinks. Personally, if he dies, I hope Callista will finally come to a much needed realisation that she's the worst mother in history of motherhood and seeing just how Evil Olivia is, how Kane and Seth have been treated, she will pull a Tali death scene from MassEffect 3. Veronica can even drop a tear in the moment, ah, such drama!
Speaking of Mass Effect (Tess apparently is aware of it at the very least) - adapting something like Mordin's death scene into the universe of KG could be cool. You'd need someone Kane trusts though, Kwame would be a good choice. Imagine - Kane agrees with the initial plans for the revolution plot, but eventually starts to see how violent and destructive it would be not just for the Karlssons, but the whole world, and decides to stop it, but Kwame, fueled by anger at his wife's treatment, refuses to stand down, so you have to take him out. 'Do you feel like a hero?' ('SpecOps: The Line' reference).
