A lot of popular media in the last fifty years has focused on the end of the world. This fascination has led to the creation of powerful characters, capable of destroying the world if they so chose. Much of these apocalypses are based on Christian mythos, where the end comes from some combination of the devil and the antichrist working against the faithful.
Not all of these characters remain bound to the religious narratives they came from, but they are all set up as figures understood to be evil. Below are the top eight most dangerous antichrists and devils, ranked by their danger levels and ability to end the world.
Cade (The Vampire Diaries)
Cade is The Vampire Diaries' devil, a powerful psychic who saw the worst of humanity and was able to create a psychic realm to punish sinners, otherwise known as Hell. Cade doesn't innately have any more abilities than a particularly powerful witch or psychic, except for his ability to create and maintain Hell, an ability only Bonnie Bennett successfully duplicated.
With all of that said, Cade is active in causing more pain in the world, but he doesn't appear to be dedicated to ending it. The catastrophe narrowly avoided in The Vampire Diaries finale was the work of Katherine after Cade was defeated, not the work of the devil himself, and even that would only destroy Mystic Falls, not the whole world. While Cade is powerful and does have servants to cause torment and death on Earth, he is not dangerous enough to end the world.
Lucifer Morningstar (Lucifer)
Lucifer Morningstar from Lucifer is one of the less powerful devils in modern media. While he has superhuman strength and reflexes, his primary power is making people share their desires. While this could easily be used against his targets, it is not an overly dangerous ability when considering the end of the world. More dangerous is his command over demons, who could end the world by doing his bidding, but that would take more work than other characters who could end the world with a snap of their fingers.
In addition, Lucifer doesn't want the world to end. Self-centered as he may be, he loves Earth and wants to be able to connect with the many humans he knows there. In fact, when there are signs that the end of the world is coming in the final season, he works against the apocalypse. All tallied, Lucifer is neither dangerous enough to end the world easily nor motivated to do so.
Damien Thorn (The Omen, Damien)
Damien Thorn is present in The Omen trilogy, as well as the A&E show Damien. It is unclear precisely what Damien's abilities are or how they connect to his destiny to end the world, but one thing is certain: Damien kills. From the first movie on, anyone who demonstrates themselves as a threat to Damien or his plans dies in a horrible way, often involving wild animals like dogs and crows.
This ability makes Damien incredibly dangerous to individuals, but it is unclear if he has any specific abilities capable of destroying the world. He does have a tendency to succeed in positions of power, seeming to control the US President in Omen III: The Final Conflict, which allows him to take up a position as British ambassador. This political sway, combined with his ability to eliminate his enemies, makes him extremely dangerous, potentially to the point of prompting the apocalypse.
Nicolae Carpathia (Left Behind)
Nicolae Carpathia is the Antichrist from Left Behind, a series of books and movies detailing the rapture and the Christian apocalypse. Going by the film version, Carpathia is a charismatic politician who is capable of making those who have faith in him believe anything he tells them. The only way to escape that power is by believing in God and performing a prayer of repentance. Other than his ability to control what people believe, Carpathia is able to handle what would be severe bodily trauma to a normal human, walking out of an explosion without a scratch.
Carpathia is dangerous because he can control other people, but he doesn't seem to have miraculous abilities like other fictional Antichrists. He cannot actually end the world on his own; he can just control people in power to end the world through military action. While this is dangerous, it can be prevented through belief in particular religious structures, which could theoretically lead to Carpathia being stopped.
Lucifer (The Chilling Adventures of Sabrina)
Lucifer from The Chilling Adventures of Sabrina has the power to give and take away magical abilities, as seen with the coven of Satanic witches. In addition, he can use the same abilities as witches and more, with the ability to read minds and a natural defense against captivity. Generally speaking, he lets others do his bidding, relying on Lilith and Sabrina to complete his plans to end the world, but he can possess mortals, particularly for the purpose of conceiving children.
One thing Lucifer does have, opposed to most other Satans and Antichrists is a knowledge of the future and desire to end the world. His prophecies generally come true, if not immediately, so his prophecy that Sabrina will end the world has a lot of validity. He wants the world ended, has seen it done, and interferes enough in the mortal world to pursue his goals.
Michael Langdon (American Horror Story)
Michale Langdon appears in American Horror Story's eighth season, "Apocalypse." He is extremely dangerous because viewers don't even see him until after watching the vast majority of the Earth's population die. Langdon successfully starts the apocalypse at the very start of the show and demonstrates later on in the show that he is capable of performing the abilities of warlocks, witches, and more.
However, Michael's innate danger is lessened by his childishness. After growing ten years overnight, who could blame him, but he is generally just wandering aimlessly under the direction of others. His obsession with defeating the witches distracts him to the point where they are able to complete a time travel spell which kills him before he can take advantage of his powers.
Lucifer (Supernatural)
On Supernatural, Lucifer possesses all the powers of an angel and more. He has the ability to take out just about any creature, barring God and his sister, and can break out of nearly any restraint. He is nearly omnipotent and omniscient, and can cast virtually any spell that a witch could.
With all of these powers, it seems like it would be impossible to stop him from ending the world if he was inclined to do so. However, he seems more inclined to take power on Earth or in Heaven, rather than try to destroy either. Lucifer's carelessness toward others' lives makes him dangerous, but his relative indifference means he probably wouldn't destroy the world.
Adam Young (Good Omens)
Adam Young is the Antichrist from Good Omens, where he is depicted as a young boy with extraordinary powers. The obvious flaw in Adam's abilities is that he doesn't actually want the world to end, but assuming he did, he would be a force to be reckoned with.
Adam is able to warp reality to his own will, inventing Atlantis and aliens in his sleep, and fully powering a nuclear reactor with a piece of candy. This is one Antichrist who doesn't have to rely on gaining political power to end the world; he could do it all on his own by willing it to be so.