With High Evolutionary will throw their way. The MCU has a mixed track record when it comes to breathing life into villains, but it seems as though James Gunn is on track to breathe life into a baddie that's not well-known outside of Marvel comic readers (and, even then, is a bit niche).
While Adam Warlock is likely to also at least start out as an antagonist in the film, there are several other villains who could make a minor appearance. Such potential for a Taserface type cameo has led many Redditors to go through the pages of Marvel's cosmic defenders, reappraising the team's most underrated villains.
The Badoon
According to Redditor dingbat046, the most underrated Guardians of the Galaxy villains are "The Badoon, baby!!!" Considering they were responsible for the formation of the original Guardians of the Galaxy, it's shocking to see how underutilized they are by Marvel.
Though the current iteration of the Guardians lack the personal connection to the Badoon that the original group did, the aliens have still proven a mighty menace for the band of cosmic misfits. This is most notable in the fact that the team had to recruit Iron Man to help defeat the aliens when they attempted to invade Earth in the 616 universe.
Taserface
When asked who the best villain was who was exclusive to the Guardians of the Galaxy, a joke in Guardians of the Galaxy Vol. 2.
While Taserface might only be known by mass audiences for his ridiculous name, the villain actually showed competency in his few appearances during the 1990s. He successfully kept control of a whole planet befor the Guardians intervened and got into further skirmishes with them before being killed by Wonder Man.
Vulcan
The younger brother of Scott and Alex Summers, Vulcan is one of the few Guardians of the Galaxy villains that originate from Earth. Like his siblings, Gabriel is an Omega-level mutant with the power to manipulate and control vast amounts of energy, powers which he used to conquer Shi'ar.
Because of Vulcan's origins as a mutant, many do not associate the character with the Guardians of the Galaxy, despite the team working to stop him in the War of Kings storyline. Despite this, Cshelton002 noted that Vulcan would be great to introduce to the MCU because "you could use him as an X-Men villain or for a cosmic storyline."
Raker
When trying to name the best villains from the Guardians of the Galaxy comics, Sure_Persimmon9302 asked, "what about Raker?" While the alien is only a small part of a greater evil in the comics (The Universal Church of Truth), he still offers a distinct face and tangible presence for the Guardians to go up against.
What makes Raker an especially intimidating presence is that he possesses the power to access the belief-battery, an object which allows the alien to do anything he believes he can do it. Because of this, Raker is able to go toe to toe with all the of the team, as well as Adam Warlock.
The Magus
The dark aspect of Adam Warlock, the Magus most famously went up against the Guardians of the Galaxy during the "Annihilation: Conquest" storyline when Warlock attempted to fix the space-time continuum. Because of this and "With Adam Warlock being around" in the MCU, genericreddit147 predicted that Magus would be the villain for Guardians of the Galaxy Vol. 3.
While Magus is one of Marvel's more powerful cosmic villains, the entity has had few interactions with the entire Guardians of the Galaxy. It's because of these scant skirmishes that many undervalue the villain as a threat to the team.
Blastaar
Frequently overshadowed by his Negative Zone companion Annihilus, Blastaar is one of many bizarre entities the Guardians of the Galaxy has squared off against, only to be forgotten about by comic readers. This is especially egregious considering his involvement in the storyline that brought the modern iteration of the team together.
While Redditors such as Cshelton002 have pointed out that "Blastarr and Annihilus" are better suited for The Fantastic Four than the Guardians of the Galaxy, the Negative Zone entity still adds color to the cosmic storylines involving the Guardians. His goal to become king of his domain gives the team a genuine moral quandary that few other villains offer.
Internal Problems
"Have been thinking about this for twenty minutes, and the only answer I can come up with is the 2008 team's internal conflicts," says thewomancallednova. While not a typical villain, the fights the Guardians of the Galaxy have gotten into with each other have proven just as dangerous for the team as the likes of Thanos.
Though the team formed in order to prevent wars from breaking out across the galaxy, the rarely saw eye to eye due to their disparate personalities. Their stability was exasperated when it was revealed that Star-Lord had instructed Mantis to telepathically coerce the into working together, a fact which led to the team's temporary dissolution.
Korvac
According to the greatest Guardians of the Galaxy villain. It's not hard to see why considering Korvac nearly caused the Earth's sun to go supernova in one of his first appearances.
Korvac's greatest achievement as a villain involved his gaining the Power Cosmic and traveling to Earth to reshape the planet in his own image. It took the combined might of the Guardians of the Galaxy and the Avengers to defeat the crazed cyborg, and even then, he still cheated death and had to be chased through time by the Guardians.
The Universal Church of Truth
Described by Redditor Benjamin_Grimm as "usually the main villain" in most Guardians of the Galaxy stories, the Universal Church of Truth is a shockingly underutilized entity outside of comics. They've appeared in more comics than any other Guardians villain, yet the institution has only been adapted once, for Marvel's Guardians of the Galaxy (the video game).
What makes the Universal Church of Truth such a threatening entity in the Guardians of the Galaxy comics is their connection to Magus. They consider the villain to be their deity and, as such, have attempted to resurrect him on numerous occasions and killed numerous non-humanoids in his name.
