The ins and outs of comic book lore can be tricky, mostly due to how continuity works. If someone is looking to read several issues in a character's life and for each of those issues to solely and consistently tell that character's story, the comic book medium is not the medium for them. Comic books are less like single narrative stories and more like urban folk lore tales, with each tale telling a different perspective for a character. There could be several different comic books featuring the same character running on the shelves at the same time, but none of those comic books would tell that character's story in the same way. This would explain away a big reason why so many characters find themselves coming back to life after initially biting the dust in a previous issue.
A comic book series could run forever, basically, and the longer that series runs, the more likely a new writer onboard may want to freshen things up by bringing back a long deceased beloved character. A character could pass on in an issue dating back to 1960, but a modern writer could revive them for a 2018 issue. That's sort of the beauty of comic books. It also explains why so many characters out there have bitten the dust and come back to life in the same breath. However, there are some rare occurrences out there where a character has bitten the dust, and stayed buried in their grave ever since. For examples of comic book characters who rose from the grave, and characters who stayed buried, read below for further details.
20 COMES BACK: THE JOKER
Just as there is no Batman without villains like The Joker, there is no Joker without Batman. They are basically made for each other, and it is hard to imagine one without the other. Which is why The Joker can never truly bite the dust. In his second ever appearance, he ate a knife to the chest, but was back by popular demand a few issues later.
Since then, we've seen The Joker burned alive, beaten down and taken out by Nightwing, snapped his own neck, and eat a super fist through the chest from Superman. And yet, he always comes back.
19 STAYED GONE: GWEN STACY
The passing of Gwen Stacy -- which Spider-Man had somewhat inadvertently caused after trying to save her as she fell -- has become something infamous in comic book culture and one of the most defining moments in the life of both Peter Parker and Spider-Man. Which is why her comic book writers were always hesitant to resurrect Stacy.
The closest we ever got was a Gwen Stacy clone that The Jackal created just two years after she was buried in the ground, and an alternate universe version of Gwen called Spider-Gwen, but the real deal has never come back from the grave.
18 COMES BACK: BATMAN
During the climax of the company-wide "Final Crisis" event, Batman was incinerated by an Omega Beam from Darkseid. For a time, it looked like that was really the end of Batman, with Dick Grayson taking up the mantle as Gotham's new Dark Knight, and Bruce's son -- Damian Wayne -- becoming his Robin.
But of course, he's Batman, and Batman always come back. As it was revealed in The Return of Bruce Wayne which hit the shelves just under two years later, the Omega Beam merely transported Batman to the Paleolithic Era. The six-issue mini-series chronicles his efforts to return to the future.
17 STAYED GONE: HELLBOY
At one point during his original run in the comic books, Hellboy is told that he is destined to one day go to Hell, overtake the throne from Satan, and become the new ruler of Hell. Since he was quite comfortable with his living conditions on planet earth, Hellboy was not in any rush or desire to fulfill his destiny.
However, with it being destiny and all, Hellboy did not exactly have a say in the matter. At the end of Hellboy: The Fury, Hellboy gets his heart ripped out, and in the final Hellboy comic -- Hellboy in Hell -- Hellboy is trapped in hell forever, and accepts that he might as well achieve his destiny while he's there.
16 COMES BACK: CAPTAIN AMERICA
"Civil War" was a catastrophic event in many ways, but perhaps the biggest tragedy to come from it was the fall of Captain America. While in S.H.I.E.L.D. custody, Steve Rogers was taken out by Crossbones and a brainwashed Sharon Carter, all orchestrated from the master plan of The Red Skull.
After two years of the shield getting passed around between Bucky Barnes and Sam Wilson, Rogers was revealed to be alive, being prepped for his mind to be taken over by The Red Skull before he fought the HYDRA leader off. Briefly, Rogers went into retirement upon his return, but in the wake of the "Fear Itself" storyline, he picked up his shield once more.
15 STAYED GONE: PEGGY CARTER
Special Agent Peggy Carter was deeply entranced in a romance with Steve Rogers. When Rogers's plan crash landed into the freezing water of the North Atlantic as Captain America during a mission, Rogers was considered M.I.A. and D.O.A. from his ordeal. Peggy merely moved on afterwards.
Decades later, when Peggy is in her old ailing age as a senior citizen, Steve Rogers returns unaged. A scene like this is depicted in Captain America: Winter Soldier, where he meets with an Alzheimer's stricken Peggy. In the next film, Captain America: Civil War, he visits her one last time for her funeral.
14 COMES BACK: PROFESSOR X
There are several occasions throughout the history of the X-Men comic books that the very face of the X-Men -- Professor X himself -- has bitten the dust. One of the more infamous instances came when his star pupil and leader of the X-Men, Cyclops, found himself possessed by the Phoenix Force and while under its control, he wipes out his beloved professor.
After spending hundreds of years in an Astral Plane, Charles is able to make a triumphant return among the living after finishing a mind battle with The Shadow King. With the help of other mutants within the Astral Plane, Charles is able to break free from his astral shackles.
13 STAYED GONE: KAREN PAGE
Karen Page was Daredevil/Matt Murdock's longtime love interest, but things took a drastic turn for her character in the canon altering epic, "Guardian Devil." This was actually a rocky story arc for Ms. Page. It starts off with Karen leaving Matt in hopes of trying to find herself. Later on, she finds out that she contracted the HIV virus from her time in a seedy line of work.
Things reach the pinnacle of bad when Daredevil fails to prevent Karen's demise at the hands of his sworn enemy, Bullseye. To honor her memory, Matt names an alleged antichrist baby after Karen.
12 COMES BACK: MAGNETO
There was a time when Magneto was thought to have perished during Casandra Nova's attack on Genosha, but it was later revealed in a shocking twist that he had actually been masquerading as a Chinese mutant named Xorn underneath a helmet. When he returns, he takes out Jean Grey, to which he gets his head taken off by Wolverine.
In a bizarre retcon, it turned out that Xorn was not actually Magneto, but instead merely an imposter masquerading as the Brotherhood leader for clout. Regardless of the retcon, it still turned out that Magneto was alive the whole time, going incognito someplace else.
11 STAYED GONE: ROBERT KELLY
While Senator Kelly was initially introduced as an anti-mutant politician, he eventually has a change of heart after Pyro saves his life. As a result, Kelly starts to openly campaign heavily for laws that bring mutants and humans together rather than separate them.
This new light which Kelly sees does not sit well with most of Kelly's long time supporters, and so one of his former supporters assassinate him in cold blood, while accusing Kelly of being a "race traitor." Kelly was never resurrected, but it's better for his story to end like this -- poetic even. To go from being an enemy of their mutants, to his life ending as an advocate for them.
10 COMES BACK: BARRY ALLEN
In 1985's "Crisis on Infinite Earths" storyline, Barry Allen sacrificed himself to stop the Anti-Monitor's plan to destroy the five earths while they were merged together. He does so by creating a speed vortex to suck up power from the speed vortex to suck up the power of the anti-matter, but in the process, Allen also sucked the life out of himself.
Several years later, during the "Final Crisis" event, readers discovered that Barry Allen had actually been trapped inside of the Speed Force all of this time. Thanks to efforts designed by Eobard Thawne (better known as Zoom), he is able to return to our reality in one piece.
9 STAYED GONE: CAPTAIN GEORGE STACY
In addition to being a key member of the New York City Police Department, Captain George Stacy also served as the father of Peter Parker's girlfriend, Gwen Stacy.
He had always suspected Spider-Man and Peter Parker of being the same person, and after sacrificing his life to save a little boy in the line of duty, Spider-Man is there by the Captain's side to hear his final words: "Be good to her, son! Be good to her. She loves you very much." Aside from a clone version of the man, we never saw Captain George Stacy in action ever again.
8 COMES BACK: ROBIN (MOST OF THEM)
If there is only one perk of donning the Robin costume for Batman, it's that Robin is guaranteed to never stay buried. There's never been a Robin who stayed permanently gone. Jason Todd was blown up by The Joker, but came back as The Red Hood.
Stephanie Brown bit the dust herself, but it was later revealed that she only faked her demise to protect herself from Batman's villains who wanted to use her against Batman. Even Damian Wayne gets his life taken by the Heretic, only to later be resurrected by Batman.
7 STAYED GONE: RICHARD AND MARY PARKER
For as long as Spider-Man has graced comic book shelves everywhere, it has been well established that his birth parents -- C.I.A. agents Richard and Mary Parker -- perished in a plane crash during a mission, which is why Peter always lived with Uncle Ben and Aunt May.
They never rose from the grave because, well, they never needed to. There was a never a Spidey storyline that demanded the return of his secret agent mom and pop. The closest we ever get to it were two life decoy robot models created by The Chameleon. The real versions of them remain D.O.A.
6 COMES BACK: JEAN GREY
In an act that is fitting of her Phoenix alias, Jean Grey is always destined to have one foot in the grave, and the other foot ready to make a leap back among the living. The first example that springs to mind is in 1980 when Jean Grey first became the Phoenix, and put an end to herself as it was the only way to stop the Phoenix Force.
It was revealed that wasn't Jean at all, but the Phoenix in disguise while Jean sat in a healing pod. The last time Jean passed away was in 2005 at the hands of Magneto, only to be replaced by a younger version of herself.
5 STAYED GONE: JONATHAN KENT
Superman's adopted father typically passes away in some way or another as a means to advance Superman's character arc, and never gets revived so that those repercussions stick. In Man of Steel, Jon's life is claimed by a bad storm, but its a different story in the comics.
After discovering that his son had fallen at the hands of Doomsday, Jonathan Kent collapsed of a heart attack. By time that he got to the hospital, Pa Kent's heart stopped. It would be restarted when he would bring his son's soul back from purgatory, but he passes on for good when he has another heart attack in 2008 after dodging a missile from Brainiac.
4 COMES BACK: SUPERMAN
Superman was America's first ever introduction to comic book superheroes, and remains the world's most popular and instantly recognizable hero on the panel. There is NO way anyone in their right mind is going to let Supes bite the dust for good.
The closest he ever came to it was in the infamous "Death of Superman", where the Man of Steel met his demise at the hands of Doomsday, only to return shortly afterwards donning a black suit and a lack of powers -- though he eventually got those back too -- emerging from a regeneration matrix inside of The Fortress of Solitude.
3 STAYED GONE: UNCLE BEN
There used to be a saying in the comic book industry that pretty much stated that the only characters who ever stayed buried were Jason Todd, Bucky Barnes, and Uncle Ben. This phrase was first coined back in the '80s, and since then, we have seen the triumphant returns of both Jason Todd and Bucky Barnes.
And yet, Uncle Ben still has a gravesite with his name on it where his soul rests. Frankly, he should remain in the grave no matter what since his mugging is the essential reason why Peter Parker became Spider-Man. It's way too important of an origin story to mess with those repercussions.
2 COMES BACK: SPIDER-MAN
The final issue of Ultimate Spider-Man sees the demise of its title character in a heroic sacrifice. In a big fight against Norman Osborn, Spidey finds himself surrounding by friends and family -- most notably Mary Jane Watson and Aunt May -- trying to protect them.
In a last ditch effort, Spidey lifts a truck above his head and squishes Norman with it. Unfortunately, the truck spontaneously combusts before Peter can evade it, and cannot recover from his wounds. While this universe's Spidey was downed, he typically doesn't stay buried because he's Spider-Man. This is just one of several examples where Spidey bites the dust.
1 STAYED GONE: ALEXANDRA DEWITT
Alexandra DeWitt was the girlfriend of Kyle Rayner. One day after a battle, he came home to find out that his girlfriend had not only been strangled to lifelessness by Major Force, and stuffed inside of the refrigerator. This kickstarted an entire trope term called "Women in Refrigerators," which refers to female characters who get nixed off in favor of advancing a male character's storyline.
It once seemed as though Alex would be brought back to life, but this new version of Alex turned out to merely by a projected construct formed from a Black Lantern.