The world of comic books has blown up in the 21st century in a way few could have predicted. A lot of this is due to the tireless standard-bearer of this cultural revolution, Marvel Comics, and its colorful chairman emeritus, Stan Lee. Lee, who passed away this week at the age of 95, is rightly credited as a comics visionary. But he was also devious and problematic, qualities mostly hidden by his talent for self-promotion. While complicated, however, Lee inarguably changed the face of our entertainment landscape, both in the niche world of comics and in the mainstream world of movie and television entertainment.

Born in 1922, Lee spent his life in the comic and magazine world, but his breakthrough didn’t come until the 1960s, when he was already nearly 40 years old. It was then that, along with the late Jack Kirby, Lee co-created “The Fantastic Four.” Together, Lee and Kirby would go on to create many comic titles still popular today, including “The X-Men,” “Iron Man,” “Hulk” and “Thor.” Lee also collaborated with comic artists like Bill Everett and Steve Ditko — Lee and Ditko created what is arguably Marvels’ most popular character, “Spider-Man.”

Lee’s biggest achievement wasn’t so much the comic characters themselves as it was the concept of fandom.

But Lee’s biggest achievement wasn’t so much the comic characters themselves as it was the concept of fandom. He put out regular newsletters (called the Marvel Bullpen Bulletin) advertising what stories and characters the publishing house was working on. He created an entirely new way of crediting comic artists, known today as “the Marvel method,” that promoted the writers and creators. He pushed the boundaries for what his writers could talk about in their stories. In fact, his refusal to tone down frank depictions of drug addiction ultimately forced the strict Comics Code Authority to update its standards, allowing more comic books to include adult themes in their stories.

Lee did much to promote comics; he also used comics to promote himself. While often associated with the birth of Marvel, for example, Lee did not create the franchise — that was Martin Goodman. Lee exploited his “Marvel method,” where anyone who added the smallest amount to a project would be listed as part of the team who created it, to give himself credit for stories he barely worked on.

Moreover, as Lee rose in the company from writer to editor to editor-in-chief and finally publisher, he did so at the expense of those he once collaborated with. Ditko left Marvel in 1966 without explanation, but most assume it was over the rights to Spider-Man, something Lee for a while insisted was his creation alone. (Lee eventually backtracked on that claim.) Kirby stayed on for decades, still writing and drawing long after Lee stopped. But by the late 1980s he had become embittered and angry over the raw deal he got. Kirby referred to Marvel as a group of “thugs” who screwed him out of royalties for his creations, while Lee was making millions playing what was perhaps his best character creation: Marvel’s "Stan the Man.”

Lee was also a problematic figure when it came to diversity. Like many men of his era, he talked the talk, overseeing the creations of characters like Black Panther and Luke Cage in the 1960s and 1970s, and regularly used his Marvel soapbox to comment on social issues like racial bigotry. But walking the walk was harder. As late as 2015, he still insisted Spider-Man films should only cast the character as straight, white and male, because that’s the way Lee imagined him. The idea that his characters could be recast or reimagined as women, or as people of color, didn’t sit well with him.

There’s a reason Marvel has struggled to find a female superhero to match DC Comics’ Wonder Woman, and it’s a simple one.

There’s a reason Marvel has struggled to find a female superhero to match DC Comics’ Wonder Woman, and it’s a simple one: There aren’t any. Lee never took female superheroes seriously, thinking them more suited for Playboy than Marvel ‘s imprint. Look at his vision for Jessica Jones, for instance, who was originally a far bubblier and feminine character than the version portrayed on Netflix. Captain Marvel, who is being played by Brie Larson in the upcoming blockbuster, was a man during Lee’s time as editor and was only gender-flipped decades later. (There are also some dark but unresolved allegations about Lee’s real-life behavior, including that he abused employees and groped nurses in his final decade of life.)

But despite a messy history, Stan Lee’s idea of putting his comics on the big and small screen inarguably changed the entertainment landscape in radical ways. Marvel’s decision to lean into Lee and Kirby’s interconnected universe concept — best exemplified by “The Avengers” — played a huge role in this impact. Before “The Avengers,” there were stand-alone superhero trilogies than focused on one character or set of characters. After “The Avengers,” though, it seemed like every tentpole franchise, both superhero and otherwise, was trying to figure out how to create crossover stoylines.

Lee also laid the groundwork for the sort of online interactions between consumer and artist that fans take for granted today. His comic book creations, even if they were not his alone, came down from their pedestals to show human and relatable sides; many of Lee’s superheroes were portrayed as flawed people who just wanted to do the right thing, not demigods. This in turn enabled a film like “Iron Man” to flourish, even as two-dimensional idealists like Superman are having a harder time getting off the ground.

Lee may have been mortal, but his ideas, like his superheroes, will never die.