This lion has been in training since cubhood to be a killer. As we know, all work and no play makes for a psychopath on its own. But day in and day out of constant brainwashing to kill this One guy is bound to make anyone a little off, and more than likely completely violently insane by the time he made it to adulthood. I propose that all that stuff in the movie that happened after rescuing Kiara was all inside his mind. He probably retreated into his 'happy place' while he killed Simba right in front of his family to a super fabricated fairy tale developed after seasons of mental and physical abuse from his obsessed insane mother.
I dunno, what do you think? Does Kovu have all the makings of being disneys psycho killer? ;P Think about it.
Kovu and Zira copyright Disney.
-DP, Die Hard Lion King fan