[Kakuzu]

A villain can be either the protagonist or the antagonist. According to Encarda, a protagonist is the main character. An antagonist is the character conflicting with the protagonist. Therefore the protagonist can be the villain opposing the hero. As long as a character is the main character, he / she is the protagonist. As long as a character is in conflict with the protagonist, he / she is the antagonist. Take Death Note for example. Light was the protagonist yet he was a villain. L and his successors were the antagonists yet they the heroes. It's all a matter of perspective. Who the main character is doesn't change their intentions. For example, if I have two fictions. One revolves around Hero. The other revolves around Villain. In FictionA, the protagonist is Hero, and the antagonist is Villain. In FictionB, the protagonist is Villain, and the antagonist is Hero. These fictions are exactly the same but written from different perspectives. Does a switch in perspective change the fact that Hero is still good? Does that change that Villain is still good? No, it doesn't. It just gives them different roles.

Kakuzu has spoken.