Marilyn rose to fame slowly but surely through her studio work in the 1940s and 1950s. Many of her earlier roles were relatively obscure (and in which she had darker hair than her iconic look) though she had a role in in All About Eve. She rose to fame later in such famous films as The Seven Year Itch, Some Like it Hot, How to Marry a Millionaire, Gentlemen Prefer Blondes and Niagara, and generally for playing the same kind of character.
Marilyn is best known for her glamourous lifestyle which was made famous in the golden age of Hollywood films. She rose to fame based more on her sex appeal than acting ability. This sex appeal was displayed in various ways among them appearing in early issues of Playboy or conversely helping to establish red lipstick as a glamourous addition to a woman's makeup options. She was also known for her high profile marriages and love affairs. As an iconic female character she has shown up periodically in comic books though generally not as a main character. Despite the fact that she is quite famous as an actress, her career trajectory in Hollywood was somewhat typical of the time, especially for an actress relying on her looks in the Big Studio era. Numerous times throughout her career she was under contract and paid far less than other actresses that she worked with. She was also beholden to acting in movies even if she wasn't interested, which led to her being cast in many comedies, which were often more forgettable than iconic. Her first appearance in comics was in Panic #5. Her last appearance while she was still alive was in Superman's Pal Jimmy Olsen #56 in 1961(technically though this was not even her, it was a look alike to make Lucy Lane jealous.) Unlike the majority of her appearances, this one predated her death and the majority of her appearances since have been posthumous.
Major Story Arcs
Generally in contemporary comics, when Marilyn does show up is either in a cameo role, or as a personification of female beauty, thus she does not have any real story arcs. An exception to this is in Vertigo Comics, where in The Sandman series of Vertigo comic books, she made a brief dream appearance in the 1st issue. As one of the people to guard Dream, Mort Notkin dreamed he was at a party dressed as a clown, and many very famous stars, like John Wayne, Elvis Presley, and Marilyn, laughed at him.
In the third issue of Mind The Gap, Elle communicates with her best friend to try to let her know that she still maintains some level of consciousness. She does this by interfering in one of her dreams where she incorrectly named Marilyn' co-star in Gentlemen Prefer Blondes. This references the fact that for some that Marilyn is a beloved pop culture icon to this day, and often maintains a level of cult status, especially among female fans.
Although she has never really been featured in comics, her use in them as a cameo has changed over the years. During the height of her popularity, she was a Hollywood A-List actress, and so she would show up in campier comics when characters would visit Hollywood. After her death she achieved iconic status as one of the first stars to die young (alongside James Dean) as well as other unknown facts about her such as her supposed affair with President John F. Kennedy. Since then her depiction has occasionally been retrospective looks at her career but more commonly use of her in an iconic sense. She thus shows up fairly often in comedy magazines because of this.
Her likeness is often used due to its iconic nature as being easily recognizable. For instance s shapechanger appeared in her image on the cover of Mutopia X #1.
Powers and Abilities
As a real life person, Marilyn has no superpowers nor has she ever been shown to have as real life characters sometimes are portrayed in comics. Occasionally though in her portrayal in comics she will appear as a ghost or in a dream sequence, where she is not bound by the same rules of reality as the remainder of the characters. She is generally considered one of the most beautiful women ever to have lived and was seemingly quite skilled at using those looks to achieve a certain level of fame and popularity.
Despite never being featured as a recurring character, Marilyn does show up often enough in comics, if only as an homage to her classic poses. One of the most common and recurring of these is the pose from the Seven Year Itch where Marilyn stands over a subway grill and lets the subway air exchange play with her skirt. For instance, the series Grimm Fairy Tales which pays homage to other iconic females (such as Rosie the Riveter and Cleopatra) on alternate covers has used its main star (Sela) in this pose. This pose was also depitcted on issue #36 of the Exiles. There are also numerous other poses which she is credited with, many of which have become iconic in themselves to the point of not always necessarily being attributed directly to her. Additionally due to her sex appeal many individual moments in her life are often referenced such as her sultry version of "Happy Birthday" sung to president Kennedy in 1962. Her clothes have often become almost as iconic as she herself is. Her dress from the Seven Year itch is regarded as one of the most famous dresses of the twentieth century. Glamour Magazine ranked it among eight famous dresses, others have been warn by other iconic women such as Audrey Hepburn, Princess Diana and Jennifer Lopez.
As a real life character that is famous for her looks this is what she has become best known for and others have followed her, both in real life (as for example Jayne Mansfield) and in fiction in their depictions. Often times characters will be depicted in only a portion of her original look, although this is often enough to make a proper allusion.
Aside from direct cases of homage to certain poses, at certain times certain characters are drawn to resemble certain poses of hers which have become highly regarded among artists for their feminine depiction. Marilyn herself was adept at female body language and is often referenced in terms of body language descriptions. Therefore even her less famous poses have gained a certain amount of respect and reference. For instance in Alien Worlds #1 a one time only character is drawn to have her likeness, which closely resembles a publicity photo of hers from the 1950s based on body and arm position and hair style, and even more minor details such as eye brow shape and apparent cleavage.
The depiction of the character in this way in comics is not a radical departure from the rest of popular culture as many have attempted to channel her iconic image, by not just adopting elements of her character, but by direct emulation through the recreation of iconic photos.