"Avengers: Infinity War" began production last month, and Marvel recently released a behind-the-scenes teaser. The teaser gave a brief overview of the Infinity Stones, and it also showed the upcoming movie's new bad guy, Thanos.

Marvel Cinematic Universe started with "Iron Man" in 2008, and "Avengers: Infinity War" is going to be the culmination of it all. Kevin Feige, president of Marvel Studios said that the new villain will show fans why he is the biggest, the best, the baddest villain that we've ever had. He will be the most frightening villain that the Avengers have ever faced, Feige added.

According to The Washington Post, this seems even more intriguing. Why did Marvel wait on the "Guardians?" This smart decision just enhanced the must-see factor of "Infinity War." Gamora is no fan of her step-dad Thanos, and it only makes sense that the Guardians and the Avengers will come together to face him in a battle. When Thanos appeared at the end of the first "Avengers" movie, fans guessed that he is going to be the villain in the sequel.

Tom Holland's Spider-Man is also intriguing, because no one ever predicted that Spidey will be a part of the big battle with Thanos in an Avengers movie. According to The Mercury News, "Avengers: Infinity War" really is an unprecedented culmination of a series of films interlinked together.

Feige said that this has been set up ever since "Avengers 1." "How do you do that in a way that is unexpected, that pits the Avengers against somebody who is more powerful than anyone they faced, and yet make them completely unprepared to face them? Well, tear them apart, which is why we did 'Civil War' before 'Infinity War," he concluded. "Avengers: Infinity War" is set to be released on May 4, 2018.