Biblical Bad Guy

The bad guys from The Bible are well known and as such don't require introduction, and everyone knows they are evil. The really handy thing is that many of them are regularly theorized to be cursed with immortality as part of their punishment for being bad guys, providing a decent reason for them to show up in any time period.

Note: Satan, Evil God, and the Horsemen of the Apocalypse have their own tropes. See also the Name of Cain.

Anime and Manga

 * The Protagonist of Rurouni Kenshin (while not named Cain) may be a Shout-Out to him; an individual who is Walking the Earth with a mark on him after committing murder.
 * Guess what the name of the big bad in Trinity Blood was. Go ahead.

Comic Books

 * A recent DC comics revelation is that.
 * Maybe. A group called the Order of the Stone did some sort of magic ritual with the Spear of Destiny, causing Cain to be reborn in Savage. Whether he actually was Cain, or just being possessed or something, is up in the air.
 * Cain is also theoretically present in the DC verse due to his presence in The Sandman, where he and Abel became part of Dream's realm. It's implied, however, that he and his brother aren't the biblical Cain and Abel, but are instead symbols of the first sentient being to ever willingly kill another member of it's species. They were then inducted into the dreaming as the archetypes of the original murderer and victim, so while we see them as Cain and Abel, other species would see someone else. One character describes their existence as the "ghost of a memory of someone who, one suspects, never existed in the first place", as a result this is feasibly compatible with the above fact about.

Oral Tradition, Folklore, Myths and Legends

 * Grendel is sometimes portrayed as Cain in later adaptations. What we have of the original was rewritten to include Christian elements, so this isn't particularly surprising (though the wording it uses would imply a descendant of Cain.)

Tabletop Games

 * In Vampire: The Masquerade, the first vampire is named "Caine" and is the Cain from the Bible. In Demon: The Fallen (in the same universe), it's noted that Caine invented murder and the killing of sentients.
 * Though in the vampire mythology Caine was The Messiah who righted wrongs and punished the wicked.
 * Cain is also alluded to in the Video Game Vampire: The Masquerade Bloodlines. Playing as a Malkavian, you realize this when . You would Go Mad from the Revelation, but, y'know, you already are.
 * According to the in-universe Vampire scripture The Book of Nod, Caine spent a good amount of time with Adam's first wife Lilith, who taught him all about the Disciplines. It's not quite clear what she is, but she definitely had some sort of supernatural power and probably wasn't a Vampire herself, at least not in the same way that Caine was.
 * Wraith: The Oblivion suggests she might be Grandmother.

Video Games

 * Cain is the name of a character that appears in Galerians, and turns out to be
 * in Devil Survivor, rebel against God. Granted, this is Mega Ten, so YHWH kinda deserves it.
 * On a lesser note, Jezebel.
 * Acctually, YHWH's evilness is subverted here. He's mellowed out a lot since the 90's. What that says about, though...
 * However it is implied in Overclocked that YHWH He also hasn't mellowed out at all in the other games either.
 * It is hinted at that the Nod commander Kane in Command & Conquer is... Cain. Evidence for indicates that he is shown to be the same age during the 1940s, he survives an Ion Cannon blast that he embraces and when assumed to be be the Biblical Cain by followers does not deny it.
 * In the rather poorly recieved final chapter known as Tiberian Twilight, it is revealed that Cain is
 * In Assassin's Creed II it's revealed in the optional glyphs that Cain killed Abel

Web Original

 * Subverted in the SCP Foundation-verse. Cain is actually a nice guy (and in this world, that's saying something), only harmful to plants due to his Enemy to All Living Things status. His brother Abel on the other hand... Cain has also stated he knows about his brother but refuses to take part in any research involving him. Just how they ended up this way is open to the readers' interpretations.

Comic Books

 * Judas showed up in Marvel for a while... during the Clone Saga, and probably in other places too. A Dr. Judas Iskariot. And somehow, everybody's surprised when he turns out to be a supervillain with supernatural powers. Turns out he's been researching 'The nature of evil', since back in biblical times...
 * If you mean Judas Traveller (yes, with two ls), it was eventually retconned (like everything else was in that mess) that he was a former criminal prosecutor turned crazy mutant Master of Illusion who only thought he was a Reality Warper. He was supposed to be a Fallen Angel at one point.
 * One of the four origins of the Phantom Stranger (a member of the Justice League) is that he is the actual Judas eternally doing penance for his crime. Not likely true, as the other three origins he has given directly contradict it.

Film

 * The Librarian has Judas as the first vampire.
 * In Dracula 2000
 * Interestingly,.

Literature

 * Not a direct example, but The Knights of the Blackened Denarius in The Dresden Files get their powers from 30 silver coins, each with a fallen angel inside. The coins are heavily implied to be the 30 coins that Judas was paid to betray Jesus.
 * Nicodemus, leader of the Knights, also wears the noose Judas hung himself with as a necktie; it offers him protection from anything..

Theatre

 * Jesus Christ Superstar actually deconstructs this.

Video Games

 * In one of the Ultima games you can recruit an ally named Saduj. Guess how loyal he is.....

Western Animation

 * On South Park, Haman was depicted as an Eldritch Abomination that the Synagogue of Anti-Semitic Jews wants to summon to take over the Jewish people. (Yeah, they were just reveling in Artistic License Religion on this one.)

Film

 * "The Girl" who accompanies Dean Corso throughout the events of 1999's The Ninth Gate is all but revealed to be the Whore of Babylon at the end of the film.

Video Games

 * In Agony, the Red Goddess is the Whore of Babylon, while The Dragon to her is the Beast of Revelations.