If you were lucky enough to see Shazam! at one of its early screenings, or if you didn’t and are looking forward to seeing it for the first time this weekend, you might be wondering about Dr. Sivana. Played menacingly by Mark Strong, Sivana proves to be quite a handful for Billy Batson as he discovers the power, responsibility and danger that comes with being a superhero. But who is he? If you’re not that familiar with Shazam and his world, Sivana may be entirely new to you. After all, this is his first time appearing in live action—well, unless you count 1979’s Legends of the Superheroes, but we’re not going to count that. But what Sivana lacks in immediate contact recognition and fame, he more than makes up for in sheer, relentless tenacity and brilliance. It’s a pretty lethal combination when mixed together with his super villainous ego and superiority complex.

In short, Sivana is not a very good dude, a fact that Billy Batson will more than happily attest to.

The story of Thaddeus Bodog Sivana actually begins all the way back at the start with Whiz Comics #2 in 1940. That number may make it look like Sivana appeared in Billy's second adventure, but that's not actually the case. Here’s a fun bit of comics history trivia for you—there was no Whiz Comics #1. Shazam also debuted in Whiz Comics #2, so Sivana and Shazam share a first issue. That was fitting since, all told, Sivana was a featured antagonist for more than half of Billy's original adventures. Not bad for an incredibly bad guy.

Back in the Golden Age, things for Dr. Sivana were...well, a little weird. He was sort of your quintessential 1940s evil scientist, but with a pretty unique backstory. Of course, Sivana didn't start out evil. In fact, he was actually a pretty good person at the beginning but was driven mad when big businesses and investors called all of his humanitarian ideas insane. Dejected and full of self-righteous fury, Sivana did what anyone would do in that situation and moved to Venus.

In the Golden Age, it really was just that easy. Trust us.

Anyway, on Venus—which, by the way, is totally populated by aliens, don't worry about it—Sivana worked even harder to develop his inventions and soothe his battered pride, earning himself a pretty high status on his adopted planet and the ego to match. If he weren't already a megalomaniac by the time he left Earth, he was absolutely one by the time he decided to return.

Unfortunately for him, things had changed in the years he'd been away and Billy Batson had become a superhero, able to foil each and every one of his devious schemes before they really amounted to anything. However, it is pretty important to note that he was the original person responsible for resurrecting the long dead ancient Egyptian monarch, Black Adam, with his resurrection machine. So not every attempt at world domination was a total flop.

Over the years, Sivana evolved and changed as Billy did. When Geoff Johns and Gary Frank reintroduced Shazam as a part of the New 52, Sivana’s origin became slightly less absurd—the Venus bit was dropped entirely—and more focused on his family, who were beset upon by some horrible plight Sivana felt only magic could cure. This led him to an obsession with the Black Adam legend, and subsequently, empowered him.

This modern-day version differs pretty dramatically from the original in that this Dr. Sivana was blasted with energy from Black Adam's tomb, which infused one of his eyes with the ability to actually see magic—a pretty major asset for someone looking to hunt magic down.

If you’ve seen the movie and are familiar with Johns and Frank’s Shazam comic, you know that it’s their take that’s closest to the Dr. Sivana that you see onscreen. This version of Sivana was less of a caricature. No longer a stooped old man in a lab getup, he’s now an intimidating middle-aged guy in a fashionable coat with a glowing eye. In other words, precisely the sort of villain brought to life by Strong.

Of course, there are some key differences between the Johns/Frank Sivana and the big screen one, but no matter the incarnation, there’s one thing about this longtime villain that is always true: some part of him believes he's doing the right thing. Sure, the "right thing" might be filtered through an extremely selfish lens, but he's rarely acting out at face value. It's this egomaniacal belief in himself and his righteousness that spurs him on, past the pitfalls of a stereotypical evil genius and into the perfect position as Shazam's greatest enemy. After all, it takes a special sort of person to be the arch nemesis of a teenage superhero, and if there's one thing Sivana is certain of, it's that he’s extremely special.

Shazam!, starring Zachary Levi, Asher Angel and Mark Strong, arrives in theaters Friday. For more on DC's latest movie, click here.

Meg Downey covers movies, TV and comics for DCComics.com, and writes two monthly columns for the site"Gotham Gazette" and "Relationship Roundup." You can follow her on Twitter at @rustypolished.