I guess my vote just made a tie.

I like adult Kovu better. I like more complex characters with inner struggles (Simba, too), and just find the man vs. himself (or lion vs. himself, rather) battle much deeper and more involved than something like the battles between Simba and Zira, which are superficially simple. Kovu's inner battle between both sides of himself adds a deeper level to the story. The main characters in SP don't have as much depth as do the characters in the original. Since Simba and Nala take on minor roles in this film, I think we are okay with having just personalities and not developed characters. However, since Kiara and Kovu are the main characters, we expect to have a broadened and more in-depth view of their characters. I think that is why a lot of people are disappointed in the character of Kiara, because she doesn't have much depth to her. Compare her to Nala in the first film, and Nala's role seems to have a lot more weight. (I'm talking adults here, not cubs.) Overall, I think this was one of SP's main flaws, and why it couldn't quite live up to the magnitude of TLK. Just compare everyone: Scar's character is much more complex than Zira's, Nala's more than Kiara's. Although people would've like to have seen more of Nuka and Vitani, people aren't disappointed in them because of their supporting roles. Timon and Pumbaa don't have a lot of depth to them either, and they correlate roughly with Nuka and Vitani. Adult Kovu is really the only character with any depth to him at all, and he correlates roughly with Simba. Simba's character seems to have more magnitude than Kovu's, but I think that's just because we traveled with Simba through the movie, whereas, we swapped back and forth between Kovu and Kiara in SP and didn't see much of their cubhood. We also didn't get to see any of Scar with Zira or Kovu, so the weight of the "evil" side of him is something we can't really compare with the "good" side, which we get to see as he spends time with Kiara and Simba.
Wooh, sorry for the essay. Hope it makes sense!! (I also don't really think cub Kovu is that cute, so 1 more point for adult Kovu,

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