Spoilers for Avengers: Mech Strike #3 ahead!
The Celestials are some of the most powerful beings in the Marvel Universe, and recently both the King in Black and Kang the Conqueror have used dead Celestials to further their schemes of conquest.
Created by the legendary Jack Kirby, the Celestials first appeared in 1976’s The Eternals. A race of gigantic, armor-clad aliens, they travel from planet to planet, experimenting on lifeforms and unlocking their genetic potential. Then, millennia later, they return to judge the results of their handiwork - and if a species is found unworthy, they are exterminated. Despite their great power, Celestials can be hurt and even killed; the King in Black not only was able to kill Celestials in one swipe with his Necro Sword, but as seen in King in Black #2, he can enslave them as well. Furthermore, Avengers Mountain, the current headquarters of the team, uses a dead Celestial as its base, and now in Avengers: Mech Strike #3, Kang the Conqueror has used that Celestial to unleash havoc on the timestream.
In a previous issue, Kang, using both the Celestials’ technology and his own, unleashed havoc on the timestream, causing the barriers between eras to collapse, seemingly killing Black Panther as well. In this issue, written by Jed MacKay with art by Carlos Magno and colors by Guru-eFX, readers get to see the aftermath - hordes of dinosaurs are now running through the streets, adding to the heroes’ problems. They must also contend with barbarian hordes and Martian invaders from the future as well. The Avengers, wearing their mech suits, push back against Kang and the invaders, and when all hope seems lost, they find a most unlikely ally: Thanos!
The Celestials are still shrouded in mystery, but there is no doubt they are quite powerful - they are capable of creating extinction-level events and have access to technology beyond the grasp of most sentient species. But for all their great power and science, the Celestials can still die, but even in death they are quite powerful, so much so that both Kang and the King in Black used dead ones to achieve their goals: Kang to rewrite reality and the King in Black to draw power for his Necrosword. Using a dead Celestial is a strategy only for powerful players like Kang and Knull, putting it out of the reach of most villains.
The Celestials are the oldest and most mysterious races in the Marvel Universe, and they are also its most powerful. Both Kang and the King in Black are aware of this and have corrupted Celestials to their own ends. King in Black and Avengers: Mech Strike are both available now in print and digital.