The MonsterVerse has introduced some of the most dangerous Titans from Godzilla's history. Most recently, Godzilla was forced to defend his title as King of the Monsters from Kong and barely survived the onslaught of MechaGodzilla. While it seems like nothing can stop the reigning champ, there is one enemy that he has yet to fight that came from the same place as King Ghidorah: space.
In Godzilla: King of the Monsters, it was confirmed that King Ghidorah was an invasive species from outer space, quietly confirming the existence of extraterrestrials in the MonsterVerse. SpaceGodzilla was an alien threat that first appeared in the Heisei era film Godzilla vs. SpaceGodzilla. His origins in the film were never confirmed but were theorized to be a mixture of Godzilla's DNA fused with a crystalline structure in a black hole. However, his creation in the MonsterVerse could be completely original while borrowing some of the sources' influences.
Rather than his birth being in space, the crystalline meteor that becomes SpaceGodzilla could crash into the Earth, attracted to the massive spike in radiation that the Titans give off. Crashing in the ocean, Godzilla may move in to inspect the alien structure, inadvertently melding his DNA with it. At this point, its evolution could begin, slowly forming its Godzilla-like appearance over the course of the film's first act.
SpaceGodzilla is a much more intelligent threat than MechaGodzilla and King Ghidorah, and the application of its abilities evidence this. Like Godzilla, the extraterrestrial can fire a beam from its mouth. But unlike Godzilla's straight beam, SpaceGodzilla can control its direction mid-blast. Its most useful abilities are tied to the crystal growths on the Titan. Massive shoulder crystals aid in its ability to conduct energy and fire bolts, while the crystals on its tail have enough power to be used as a stabbing weapon. Its most powerful applications allow SpaceGodzilla to form a shield and grant him the ability to fly.
King Ghidorah established that alien threats are much stronger than Godzilla and often require more than one Titan to defeat them. Godzilla might learn how strong his enemy is after losing to him in the film's first fight. To combat this threat, a lingering plot thread from the end credits of Godzilla: King of the Monsters could finally pay off. In the film, Mothra appeared as the Queen of the Monsters and sacrificed herself to give Godzilla a power boost to kill Ghidorah. But during the credits, it was confirmed that a new egg was found. The egg is the perfect opportunity to bring Mothra back for another battle.
The final battle could then have Mothra and Godzilla teamed up against SpaceGodzilla, with the former covering the sky and the latter handling the ground. While SpaceGodzilla may inflict massive damage on both monsters, their combined power could overpower the evil Titan. Being tied down by Mothra's silk, SpaceGodzilla's hide could be exposed to Godzilla's atomic breath, allowing the King to annihilate him, similar to how he disintegrated King Ghidorah. Each new threat has become even stronger than the last, and the massive strength of an alien threat like SpaceGodzilla is the perfect follow-up to King Ghidorah.