Sasuke is the example of a good and happy kid, who got through a tragedy. He uses only his hatred as a motivator and it is shown to work quite well for him.
But deep down his hatred comes from love.Yeah that’s right LOVE. He loved his parent and relatives a lot. And he loves even more his big brother Itachi.
Let me say a few words about his fighting style and his jutsu. Compared to Naruto, Sasuke can use 2 elements, has far better training, and knowledge. He also uses far more strategy when in a battle and most of the times calm.
First of all he’s an Uchiha and has not only the Sharingan, but the Mangekyou Sharingan(which he awaken some time before he killed the entire Uchiha clan.
Itachi has always been a piece-lover(he hates war) but just had the bad luck of growing up during the 3rd Great Ninja War.
I admire how he’s always so calm and analytical and almost unbeatable.
He did everything to protect his little brother (Sasuke Uchiha). But to tell you the truth he had no choice in one scenario he would do what he did in the other there would spring another war if the Uchiha clan started it.
He also is powerful enough to defeat Nagato(Pain) alone. And not to forget that he fought Sasuke, while in pills.