Knight of Cerebus/Comic Books

• Cerebus didn't actually have one of these; the major turns for the Darker and Edgier usually (but not always) involve the scary-as-hell matriarchal fascists called Cirinists, but there's no one character that fits the bill.
• During the 90s comic book phase of 'grim and gritty', DC's Justice League was played for laughs by Giffen and DeMatteis until the arrival of Despero in JL #38 and his subsequent killing spree (including killing a team member's parents) and introducing a new 'serious' phase in the history of the book... whose readership then tailed off.
  • And with the advent of Infinite Crisis Justice League ally Max Lord was retconned into being one of these. His recent return as a White Lantern ramps this Up to Eleven.
• The supervillain Harm in Young Justice; the first page of his first appearance is marked by Arrowette, bloodily impaled with one of her own arrows, saying "But that's n-not funny..."
• Willy Pete in Empowered gruesomely killed a bunch of people by literally raping them to death (which is all too easy for him to do, as he is a fire elemental who cannot shut off the powers that make his body superhot) in his very first appearance. Note that we're talking about a comic book that was almost purely comedic up until this moment.
  • Note that since he is a fire elemental, his raping them to death wasn't done in any of the normal ways, because the meat burned away too quickly. So he'd use an eye socket, since the skull would hold the pressure better. More durable sorts he tended to cannibalize (occasionally as they watched), since he couldn't eat normal food because it burned up in the same way; superhero meat would resist longer and be perfectly cooked by the time he could eat it.
  • Ninjette's pursuers, while having their moments of black humor, ventured firmly into this territory when they hunted her down, and after suffering much pain, decided that the best way to bring her back without further incident was to chop off her arms and legs, which she wouldn't need anyway to fulfill her destiny as a ninja baby-maker. She was saved by her friends in the nick of time, but the mental image of what they tried to do left her a bit unhinged for the whole next volume.
• Scott Pilgrim is a Wickety comic, and starts out very happy until Gideon shown up and stabbed and killed Scott and Ramona (well, Ramona almost gets killed).
  • To a lesser degree, the Katayanagi twins also messed up the comic's quirky nature.
• The appearance of the Anti-Monitor in Crisis on Infinite Earths was such an Up to Eleven example (just like everything else about Crisis On Infinite Earths) of this trope that he not only ushered in Cerebus Syndrome for the entire DC multiverse, but induced a Cosmic Cerebus Retcon upon its entire history. However, instead of taking the danger to a new level, he instead warped the fabric of reality into the Dark Age and all its Darker and Edgier '90s-ness, since no one since has ever been able to come close to either his threat level or evilness level.
• Sonic the Comic, while becoming somewhat dark as the issues passed by, really started becoming dark once Super Sonic appeared. It got even worse when he separated from Sonic.
  • Archie's Sonic the Hedgehog comic similarly started out rather lighthearted, but Robotnik was gradually made more and more into an actually menacing villain, and as he did the general tone of the series grew darker, and the constant gags and attention to construction that fueled the early installments gave way to constant peril and at least one issue that was almost entirely traced. Then Robotnik died and the comic turned to high school relationship drama, and I'll leave it up to you what effect that had on the tone of the series.
• Les Légendaires uses this at several points to different level. The serie typically stars as goofy and comical, only to turn surprisingly dark and serious whenever the major villain of the current arc is introduced :
  • Darkhell is believed dead several time, but everytimes he shows up, it always ends up with people dying. Even more extreme, the flashback show that he did a lot of horrible things in the backstory : so far, almost everything bad to ever happen on Alysia has somehow a connection to him... no wonder he became The Dreaded in all Alysia.
  • While the Guardian was more of a Lawful Neutral type than an actual villain, his role as an antagonist in book 2 caused the whole cast to die, ironically because of him).
  • While Skroa didn't really have time to cause much harm at his introduction in book 2, his come-back in book 7 and 8 caused a lot of death and almost led to the extermination of the Jaguarians. Spoilers about the next book suggest that he might do ever worst soon.
  • Anathos is probably one of the most extreme level; whereas the serie had already got quite serious and dark at this point, his appearance made the whole story goes even darker, starting with him possessing one of the protagonist, scarring or crippling all the others and almost succeeding in a genocide of humanity. Even after he was eventually defeated, the serie seems so far to retain a darker tone that it usually had.
• The Shattered Grid Arc of Mighty Morphin' Power Rangers (Boom! Studiios) give us Lord Drakkon, an evil version of Tommy Oliver from an alternate world where he exacts his reign of terror into that world. When he has Jason Scott, Billy Cranston, Ninjor, Zordon, Alpha 5, and main universe Tommy Oliver in his kill list, things began to go downhill.
• The Nodwick print comic, in order to move from the gag-a-week strips show in Dragon (magazine) into a Myth Arc, introduced one of these as a Big Bad: God of Evil Baphuma'al, who was a lot more competent and Genre Savvy than Dragon villain Count Repugsive (though, really, outdoing a villain whose first 'Evil Plan' involved going into the real estate business isn't that hard to beat...). Repugsive did get A Day in the Limelight in the print comic (where he ironically came closer to conquering the world than Baphuma'al did), but the plan was mostly Played for Laughs (it involved turning the universe into an 8-bit platforming game) and the heroes defeated him fairly handily. Repugsive inadvertently got mixed into the main storyline and ended up helping to save the day in the end; the villains attempted a Grand Theft Me scheme to upload Utharr's mind into his body, and failed because Repugsive's mind refused to let itself get entirely booted out.