1. a cruelly malicious person who is involved in or devoted to wickedness or crime; scoundrel.
2. a character in a play, novel, or the like, who constitutes an important evil agency in the plot.
That's the dictionary definition, but how about a specific one: Ray, from Breath of Fire 2. I know that most of you haven't played it, given that it's very much a cult series. I found it on the Wii's virtual console for 8 dollars. If you enjoyed Dragon Quest, Chrono Trigger, or Final Fantasy, you'd probably enjoy it. The story is on par with Final Fantasy 4. It's basically a "Go kill this" story, but it's told with such flair, and such an awesomely bad translation, that it's unique and awesome. It also started the "Church is Evil" cliche.
The main villain in the story could either be considered Habaruku or Death Evan. Habaruku is the leader of the Church of St. Eva, and a master manipulator, causing the death of this article's subject. Death Evan is a sealed demon who wishes to destroy everything for some reason... it's not that well explained. The other characters in the game are far more interesting.
Three paragraphs in, and I haven't even talked about the article's subject yet. Ray is a priest in the church of St. Eva, and meets the PCs rescuing townsfolk from monsters in a well. He grants the party a spell after this sequence, and the game goes back to it's story. Towards the end of the game, he meets the PCs, and after a disagreement over what happened to a party member's (Rand, if you played the game) mother. The PCs are suspicious of this, knowing that the stubborn character would not change her religion and give her land to the church, and decide to travel to the Grand Church of St. Eva.
After a few fetch quests, the party enters the church, and confronts Habaruku, the leader of the church. He maintains that the church is not malicious, declares the group to be heathens, and orders Ray to kill them. Ray states that he thought that they understood each other, and states that he must now slay them, turning into a huge dragon, an ability shared by the protagonist, a scion of the lost Dragon clan. The battle is not typical, and merely consists of a round, the protagonist casting a spell he learns after being hit by the dragon's breath, and kills him in one shot. Ray returns to human form, and states that he has met his equal, that the church is evil, and that he was honour bound to serve Habaruku.
Several towns later, the party travels to the village of the lost dragon clan. They see a man who looks exactly like Ray, and he says that Ray must have been a member of the dark dragon clan, the villains of the first game.