Guardians of the Galaxy 2 is a sure thing after the success of the first film. We haven't heard much about the movie, but it appears the lid is being removed after director James Gunn revealed that his favorite hero would be added to the film.
We have no idea who this hero is because Gunn did not disclose what everyone was expecting.
However, he did drop the name Nova, but later made it clear that the Nova Corps will not make an appearance. If the Nova Corps should make an appearance, it would mean Richard Rider would have to appear as well.
Now, Richard Rider is human, and Gunn stated that it is important for Star Lord to be the only human in Guardians of the Galaxy 2. Why this is the case, we have no idea, but it appears to be linked directly to the planned storyline.
Speculation began to grow rampant and thus the talking otter, Lylla, was mentioned, but Gunn shot it down. We can see why Lylla won't feature in the film because the character would take away Rocket's uniqueness as the talking Raccoon.
So, which new hero could Gunn bring to Guardians of the Galaxy 2? Well, it could be a female character. In a recent interview with Collider, Gunn stated that he hopes to add another heroine to the film but it is not sure if he plans to go ahead with this scheme.
At the end of the day, however, the big addition could be Adam Warlock, who is a prominent figure in the battle against Thanos. From the original Infinity Gauntlet storyline that took place in 1991, Adam Warlock, who is an artificial human, was seen as the protector of the Infinity Gauntlet. The hero was the original owner of the Soul Gem but ended up losing it to Thanos.
After Thanos had acquired all five Infinity Gems and the Infinity Gauntlet, Adam Warlock went out on a mission to gather a team of heroes to help him take down Thanos once and for all.
If Marvel is smart, then Adam Warlock will no doubt make an appearance. However, we do understand that James Gunn is going with an original storyline that Marvel deems as risky, so it could mean what most Marvel fans have been thinking all along; the Hulk is going into space in the aftermath of Avengers: Age of Ultron.