With every Avengers: Endgame trailer or tease comes a new wave of theories as to what the next phase could hold for our heroes. After Marvel dropped a teaser for the film during the Super Bowl, a new theory surfaced that could suggest the return of one major villain.

Read more: 'Nightmare Before Christmas' could get a possible live-action remake

Unless you've been living under a rock, you've already seen Avengers: Infinity War, but just in case you haven't...

***WARNING: Spoilers for Avengers: Infinity War below***

If you're a true Marvel fan like myself, then you were probably as equally shocked and confused as I was when Red Skull appeared in Infinity War.

Marvel is fantastic at their "whoa I didn't see that coming" surprises, which makes this newest fan theory that much more possible.

Reddit user mdv15 has come up with a new theory after watching the film's Super Bowl teaser that suggests we could see the return of a familiar villain.

"Okay, so in the Super Bowl Spot for Endgame we all saw Ronin staring at something (or someone) that was giving off a red light. His facial expression doesn’t give the impression that it’s an ally, so I’m going to assume its either a foe or a bad object."

The user continues stating, "There are two characters that emit red light when their power is activated. Scarlett Witch and...Ultron."

Could it be possible?

While there's no concrete evidence for this theory, they do bring up some good points.

Who is Ronin looking at in the Superbowl Spot? I have a theory... from r/MarvelStudiosTheories

Do you think it's possible for Ultron to make a comeback? Check out the Avengers: Endgame Super Bowl teaser below to decide for yourself.

What are your theories for the upcoming Marvel film? Give us your best ones in the comments below!

See more: The 10 most metal cartoon characters

[envira-gallery id="194728"]