Marvel has a villain problem.

Admittedly, it’s not as bad as DC, but still many people have been complaining that Marvel superhero movies consistently lack compelling and well-developed villains. After all, a hero is only as good as his obstacle. No matter how powerful he may be, a big baddie that lacks character depth will seem like a CGI punching bag that the main characters will have to pound into submission until he disappears into an unmemorable ending.

For movie fans around the world that have been eagerly awaiting the release of Avengers: Infinity War, the long wait is nearly over. This time we get to see the Avengers fight Marvel’s most powerful villain yet, with several movies building up the hype for this big reveal. We’ve seen many villains in the Marvel Cinematic Universe (since every movie needs one), and their motives have varied widely — from consuming and terraforming all life-sustaining planets in the universe (Ego the Living Planet from Guardians of the Galaxy Vol. 2) to earning a decent wage (Vulture in Spider-Man: Homecoming).

So who is Thanos, the biggest baddie of all? What is his motive, and what does he want with the Avengers? Is he going to be a convincing and memorable villain like we’ve seen with Erik Killmonger in Black Panther, or completely forgettable like Malekith from Thor: The Dark World (That’s right. “Who?”)?

Who is Thanos, and what does he want?

Thanos’s home planet is Titan, a moon of Saturn. Born from a race of superhumans, he possesses incredible strength, agility, and intellect. In the comics, he is in love with Lady Death, the personification of death, and wants to destroy all life in the universe to impress her. In the Marvel Cinematic Universe, there’s a little more to it than that; after proposing a drastic measure of wiping out half of the population of his home planet to save the rest of the race from overpopulation and shortage of resources, Thanos is exiled and earns the title “the Mad Titan.” The Titan race eventually goes extinct, and Thanos vows to carry out his original idea of killing half of the population to save the rest — on the entire universe. However, instead of visiting planet after planet to execute his mission, Thanos learns that he can do it instantaneously if he has the six Infinity Stones, which will give the owner total control of the universe.

Where are the Infinity Stones?

Said to be artifacts that predate the universe itself and used by ancient demigods as weapons, Infinity Stones are some of the most powerful objects in Marvel Comics. Five of the six Infinity Stones have been featured in the previous MCU movies. The blue Space Stone (introduced as the Tesseract) was first seen in Captain America: the First Avenger, used by the Red Skull to power Nazi weapons. In The Avengers, Loki was supposed to retrieve the Space Stone on Thanos’s bidding but fails, and the Stone was taken to Asgard by Thor for safekeeping.

Thanos already had the yellow Mind Stone, which can manipulate the minds of others and was given to Loki in his quest to retrieve the Space Stone. It resided in Loki’s Sceptre, and unfortunately for Loki, he has failed to retain both Stones, and the Mind Stone came into Tony Stark’s possession. In Avengers: Age of Ultron, the power of the Mind Stone was used unintentionally to create Ultron, before giving birth to Vision and finding home on his forehead.

Malekith tried to use the power of the red Reality Stone (introduced as the Aether in Thor: The Dark World) to take over the Nine Realms but ultimately fails (and also fails to make an impression as a villain). The Reality Stone was given to the Collector on Knowhere to keep it safe.

The purple Power Stone made appearance in Guardians of the Galaxy (introduced as the Orb), in which Ronan the Accuser was sent by Thanos to retrieve it. Ronan tried to keep the Stone for himself to use it to destroy the planet of Xandar in an act of revenge and display of power, but was stopped by Star-lord and the Guardians. The Stone was then given to the Nova Corps on Xandar for safety.

We saw the green Time Stone (introduced as the Eye of Agamotto) in Doctor Strange, used to lock Dormammu in a never-ending time loop. It resides in Kamar-Taj in Nepal under the protection of the Masters of the Mystic Arts and occasionally worn by Stephen Strange.

Soul Stone, the last Infinity Stone, is yet to be seen.

Has Thanos been in any of the other MCU movies?

Many casual moviegoers were thrown off by the sudden appearance of a purple man during the end-credits scene in The Avengers. (My befuddled friend asked me “Why did the Hulk turn purple?”) That gold-armored purple man sitting on a floating rock chair in space was Thanos, being briefed after the failure of the invasion of Earth by the leader of the Chitauri army that the humans are not to be underestimated, and that if Thanos challenges the Avengers, Death will be pleased.

The first on-screen presence (not counting the end-credits) of Thanos is in Guardians of the Galaxy. The main villain of the movie, Ronan the Accuser, is merely a pawn of Thanos. Ronan is powerful enough to kill the leader of the Chitauri army in an instant, but we see Thanos treating him like a child, even when Ronan decides to take the Infinity Stone for himself and threaten Thanos.

During yet another end-credits scene, this time in Avengers: Age of Ultron, Thanos is irked that Loki has not only failed to retrieve the Space Stone but has also lost the Mind Stone entrusted to him. “Fine, I’ll do it myself,” says the purple demigod as he puts on the Infinity Gauntlet not yet garnished with the Infinity Stones.

Thanos doesn’t make a physical appearance in Guardians of the Galaxy Vol. 2 but is mentioned by his two step-daughters Gamora and Nebula. Trained to be deadly assassins, the two sisters dueled each other from a young age and Gamora would always win; each time Nebula lost, Thanos would replace one of her body parts with a cybernetic part to improve her. Always the least favorite and never being accepted for who she is, Nebula feels a deep hatred for Thanos.

In the end-credits scene in Thor: Ragnarok, Thanos’s Warship appears, dwarfing and looming over the spaceship that Thor, Hulk, and other Asgardians inhabit. We’re excited to see if this will serve as a transition into Avengers: Infinity War.

Now you have a pretty good idea who Thanos is and what he’s after. And you also know that Marvel has put a lot at stake here and will consequently make the Avengers go through some hell before finally stopping Thanos. We want Thanos to be a good character, one that is not only menacing and powerful, but nuanced and complex as well. But a character is judged not on what role he plays in the plot, but how convincing or relatable he is in the fictional world we are led to explore. Let’s keep our fingers crossed as we strap ourselves in for the biggest ride yet in the Marvel Cinematic Universe.