Orochimaru: Satan's Serpent Orochimaru is undeniably the true villain of Naruto. Satan's serpent has nothing on this man! He is one of the Legendry Three, and is the most talented among them. But since his days of being in the Hidden Leaf Orochimaru has turned wicked. He has formed his own Hidden Village, the Hidden Sound Village which he intends to use an impetus for constant war. Before he can set his "Windmill" [as he refers to it] spinning, he needs to provide it some wind. The Hidden Leaf Village is that wind but why that specific village? Well, Orochimaru has a vendetta with the Hidden Leaf that has lasted a number of years: it stems from his power-struggle within the Hidden Leaf.
Back when he was still an Academy student, Orochimaru was an untouchable child with masses of potential to become a great Ninja. Hokage always praised Orochimaru and thought highly of him, even more than his other students. He was a very bright student and never missed a trick, but there was still something evil about him. His apperance was chilling and he never said much, his eyes usually say it all. Ever since he was small, his physical features were very snake-like. He had a long tongue, small, beady eyes and cold, pale flesh. In fact, he looks more like a snake than a human from some perspectives. As Orochimaru grew, his malice grew with him and he began to act very suspiciously. Some years later, Hokage came to choosing the Fourth Hokage. Orochimaru believed he was the best choice, because he though of himself as the most powerful being in the village. As it turned out, Orochimaru wasn't picked, and the Fourth we know, the one who sealed the Demon Fox, was chosen. This enraged Orochimaru and his bitterness lead to him conspiring to breaking rules and taking it upon him self to plan his revenge against the Third. But his ambition didn’t stop of petty vengeance. This is where we see his twisted ideology shine.
10 years before Orochimaru appears in Naruto, he was a very busy man. Taking Chuunin and Genin and even Anbu members, so he could experiment on them in order to obtain a certain Kinjutsu, a forbidden Jutsu, and become the "Ultimate Being". Orochimaru wanted everything. But that, he meant he wanted to know all the Jutsu there was to know. This, seemingly, impossible dream of his would take an eternity to realise. So, to have eternity at your will, you need to become immortal. That is exactly what Orochimaru is trying to achieve. His experiments on Ninja were to see if he could learn the secrets of The Spell of Immortality. It was for this reason, the Third had to stop him. However, the Hokage faltered. His feelings for Orochimaru got in the way when the time came to execute the bastard serpent and doing so, lead to Orochimaru’s survival.
In the time Orochimaru was away from the Hidden Lead, he became a step closer to getting immortality. He learned the Reincarnation Jutsu. A Kinjutsu that enables the user to anchor their soul to the living world but requires a new body every so often, so the spirit can endure by possessing that body. This is the spell that allows the Orochimaru cheat age. Had he not learnt this Kinjutsu, he would have looked his true age, over 50 years old. Instead, he is more youthful and beautiful than most of the people 30 years younger than him. It doesn’t stop there either. Because he is seeking to learn every Jutsu that exists, he needs something special to hasten the process. And he found the Sharingan. With a body that carried the advanced Uchiha blood in it, he could use the Sharingan to copy any Jutsu that he saw. However, since the Uchina's were bloodily massacred, only two more members exist. Uchiha Itachi and Uchiha Sasuke. One small dilemma hinders Orochimaru. Itachi is a lot stronger than him and would probably kill Orochimaru if he even attempted to obtain his body. Therefore, Uchiha Sasuke is Orochimaru's prey. And he is hell-bent on getting him!