I was just thinking, Nuka spent his entire life trying to fulfill his mother's wishes. This, of course, meant that he was contributing to very evil plans. Obviously if Zira had been good, Nuka would have as well. But if Nuka had been alive and present when Kiara knocked it into everyone's heads that Zira's notions were bullcrap, might he have changed to the good side as well?
Personally, I think he just might have turned neutral for a moment, long enough to see that his sister was joining Simba's Pride, and perhaps joined as well. I think it's kind of a long-shot though... so I'm voting "other."