As a cub, Simba was playful and always ready for an adventure with his best friend, Nala. He saw the good in everyone, even his uncle Scar. At times, he can be a show-off, and he thinks he'll be the best King ever. Therefore, he's sometimes overconfident, and he often got himself into danger. In spite of this, he comes to see the fault in his actions and acts upon the lessons he's learned.
Now as an adult, Simba was still fun-loving and optimistic, but ashamed of those actions he believed were his fault as a cub. After reuniting with Nala (who is also an adult now), Simba becomes even more courageous and is determined to protect his family and kingdom, regardless of the cost. Unfortunately, later in life, this defensiveness causes him to become occasionally overprotective and even arrogant to others, even his family. However, he eventually comes to see the light and is successful in saving his pride. Simba is marked by his strong sense of justice.
Simba once caught in battle for his world and other when the satan, Chernabog fused the Disney movie world into one.