A description on uncovered Avengers 4 merchandise that leaked Thursday teases the emergence of a threat even greater than Thanos (Josh Brolin).
The Asgardian Thor wields the mighty Stormbreaker in his battle against new foes. Rocket teams up with a new crew to guard the galaxy from an even greater threat.
Rocket's "new crew" is expected to be the Avengers, who Rocket — being the last-surviving member of the Guardians of the Galaxy with Nebula (Karen Gillan) — takes up with when seeking to avenge the fallen, who were annihilated by Thanos' Infinity Stone-powered snap in Avengers: Infinity War.
Thor (Chris Hemsworth) and Rocket (Bradley Cooper) previously teamed to travel across the stars and forge the Thanos-killing Stormbreaker, which nearly succeeded in fulfilling its purpose when it was driven into Thanos' chest by a vengeance-seeking Thor.
If rumors hold true and Avengers 4 is subtitled Annihilation as has been reported in the past week, Marvel Studios could be borrowing a plot point from the eponymous comic book crossover event which saw Annihilus, the death-fearing bug-like ruler of the Negative Zone, unleash his galactic invading army known as the Annihilation Wave on the galaxy.
Annihilus, traditionally a Fantastic Four villain, could have his screen rights tied up at 20th Century Fox, who currently control the likes of such characters like Galactus and will do so until the looming merger between Disney and Fox is completed.
Characters like Annihilus and his Annihilation Wave could be wholly-owned by Fox or the characters could exist in the same legal grey area of co-ownership that allowed Marvel Studios to utilize the Skrulls — the shape-shifting aliens typically classified as Fantastic Four villains — in Captain Marvel, despite not yet possessing the Fantastic Four screen rights.
Guardians of the Galaxy writer-director James Gunn, once the planned architect of the future cosmic side of the MCU, explained previously Disney-owned Marvel Studios was able to utilize the Skrulls because the alien race is co-owned by Disney and Fox; it's only specific Skrulls, like Paibok the Power Skrull or Kl'rt the Super-Skrull, that the studio would be prohibited from using because such characters would belong to Fox.
That same reasoning is why the Watchers — the big-headed, silent alien race glimpsed in Guardians of the Galaxy Vol. 2 — were able to appear, but Uatu, the most famous of the Watchers and traditionally associated with the Fantastic Four, went unseen or unnamed.
Alternatively, a behind-doors deal could have been made that would have allowed Marvel Studios to use Annihilus, if he is Fox-controlled and if he is involved in Avengers 4: Marvel once attempted to negotiate a deal with Fox that would have seen Galactus and the Silver Surfer traded back to Marvel in exchange for an extension on the Daredevil screen rights, as the studio was then developing a reboot under director Joe Carnahan. (Because Fox failed to get the project together in time, the Daredevil rights lapsed and were automatically returned to Marvel Studios.)
Pending that, Marvel could substitute Annihilus and the Annihilation Wave with characters they do control, as they've done with the Quantum Realm — a movie-only creation that's since been accepted as a substitution for the comics' Microverse, a subatomic universe whose rights lie outside of Marvel's reach.
Both the Quantum Realm and time travel are expected to play a major part in Avengers 4, and with the Quantum Realm being full of infinite and untold possibilities, it's possible that largely unexplored part of the MCU could be where a new — and bigger — threat emerges.
Avengers 4 opens May 3, 2019.