
This Uni-Mind (as Phastos dubs it) is effectively the equivalent of all the Power Rangers teaming up to become the Megazord, and it allows Sersi to turn the planet-sized Tiamut to stone. It seems that becoming the Prime Eternal gave her a bit of a power boost, and Phastos figures out a way to pool the Eternals' collective power into Sersi by making adjustments to the sphere that marks her as the Prime Eternal.

It's far from a morally clean decision, and on top of the internal conflict she feels over the decision, Sersi also has to contend with resistance from Ikaris and Sprite (who chooses to join Ikaris because she's secretly been in love with him for thousands of years.)Īt the beginning of "Eternals," Sersi says that her powers can't be used to affect sentient beings - but this is called into question when she rather impressively turns a Deviant into a tree. Moreover, stopping Tiamut from emerging means that all of the worlds and lives that Tiamut would have gone on to create in the universe will now never exist. When the last of the Deviants were seemingly defeated in 1521 AD, the Eternals went their separate ways and tried their best to build lives for themselves as they waited for their next mission. With that in mind, Tiamut's emergence from Earth isn't an act of malice any more than a baby being born is an act of malice towards its mother. Then one day the Celestial is "born," and that does not go well for the planet it was growing in. As intelligent life evolves and grows on the planet, like humans did, the fetal Celestial draws on the energy being created by the surface-dwelling inhabitants and uses it to grow. The only way that such a being can be created, Arishem tells Sersi, is by planting the seed for a Celestial at the core of a planet.

The brain, bone, and other matter from the Celestial's head generates enough wealth to support a small economy on Knowhere, and in a flashback courtesy of the Collector, a Celestial was shown wielding the Power Stone to wipe out an entire planet. The sheer scale of them was first hinted at in "Guardians of the Galaxy," when the ragtag team of space misfits visited the mining colony of Knowhere - built in the empty skull of a dead Celestial. These are the most powerful known entities in the Marvel Cinematic Universe. Why? The answer lies in how new Celestials are born.
