With Avengers: Infinity War just around the corner, fans of the MCU must ask an important question:

What's next?

Aside from the likely additions of the Fantastic Four and the X-Men, the most intriguing part of the MCU's future is who will replace Thanos as the franchise's big bad. Either Marvel could try to up the level of the threat, which is no easy task, or they could try to go a bit more personal. Luckily, especially with the newfound access to X-Men and Fantastic Four characters, Marvel has a lot of villains that would make for fitting replacements for Thanos. Along with naming five potential villains that could serve as the next main villain for the MCU, I am also going to name some actors that I could see playing these parts.

Without further delay, lets begin:

5. Kang the Conqueror

This frequent enemy of the Avengers in the comics would make for a particularly intriguing big villain. His power is similar to that of Thanos, as he pretty much rules the universe in the future. The fact that he is a time-traveling conqueror also has the possibility to challenge our heroes by asking themselves provocative questions. Is all the good work they did meaningless? Are they truly the masters of their own destiny? These questions would for an amazing philosophical challenge for the heroes, along with Kang's physical threat.

Who Should Play Him: I could definitely see someone like Javier Bardem playing this type of character. Bardem would be able to give this character a creepy vibe to him that would make for wonderful possibilities.

4. Galactus

If you want a villain whose power easily trumps that of Thanos, Galactus is your guy. I mean, how much more powerful can you get than I guy who eats planets? Good thing that the Fantastic Four and X-Men will be joining the MCU soon, because our heroes are gonna need all the help they can get if Galactus is the franchise's next big bad guy.

Who Should Play Him: There's just something so cool about the idea of Peter Dinklage voicing this giant character.

3. Norman Osborn/The Green Goblin

If you're looking for a more personal big villain for the MCU, Norman "Green Goblin" Osborn would be a perfect choice. While most people see him as strictly a Spider-Man villain, he has proven to be formidable threat to the Marvel Universe at large in the comics. Just make sure you give him a comics accurate costume this time around.

Who Should Play Him: Call me crazy, but I think Steve Carell would make for a great Norman Osborn. Most people associate him with comedy, but he has proven to be a strong dramatic actor in the past.

2. Baron Zemo

Who said that the next big villain for the MCU had to be a completely new character? With all the hype heading into Infinity War, many people have forgotten that Zemo from Captain America: Civil War is still alive. This is a character that managed to rip the Avengers apart by the seams without ever fighting them. If he was able to do that without superpowers, imagine what we could do if he gets his hands on some good weaponry. Having Zemo as the new big bad guy of the MCU could also pave the way for the introduction of the Masters of Evil team Zemo leads in the comics. Such an introduction would lead to the Avengers fighting a team of super villains, something we have yet to see in the MCU.

1. Doctor Doom

Of all the exciting possibilities created by the likely and eventual additions of the Fantastic Four and X-Men to the MCU, the concept of finally having a great movie portrayal of Doctor Doom stands out. Doom presents a happy balance between having the next MCU big bad being a physical threat comparable to Thanos and being a much more personal threat. Simply put, he can kick your ass, but also ruin you at a personal level.

Who Should Play Him: I think Oscar Issac would be great for this role. I know that he turned in a sub par performance as Apocalypse in the previous X-Men film, put I think it says more about what he had to work with than him as an actor. I believe that Doom is a role that better suits his talents.