This article contains major spoilers for Zack Snyder's Justice League. You have been warned.
- "They're change machines. The Boxes don't think in terms of healing or killing, alive or dead. They rearrange matter at the will of their masters. Regenerate. Reinstate."
A Mother Box, also called a Change Engine, is a perpetual energy matrix of Apokoliptian origin. The three Mother Boxes present on Earth arrived alongside Darkseid during his attempted invasion thousands of years ago, but were subsequently left in the hands of the Amazons, Atlanteans and humans.
During Steppenwolf's attack on Earth, the Mother Boxes were used to revive Superman by the Justice League to fight off the Apokoliptian warlord and were successfully separated, preventing The Unity's energy from terraforming the Earth.
Thousands of years ago, Darkseid led an attack on Earth. Darkseid brought forth three Mother Boxes with him to use to terraform the Earth into a planet similar to Apokolips. However, Darkseid was defeated by the alliance of mankind, the Amazons, and the Atlanteans, with assistance from the Old Gods and the Green Lantern Yalan Gur. The Mother Boxes were successfully separated by Zeus, left for the forces of Earth to guard. While the Amazons and the Atlanteans kept theirs guarded in vaults, mankind buried their Mother Box so that nobody could ever find it again.
After the bombings in Liege, along the western Belgian front, a powerful object, believed to be the Mother Box was found by the Allied Powers during World War I. They sent the Wonder Men led by Etta Candy to investigate and retrieve the object, providing them with a picture of a Mother Box.
Whether the mission succeeded or not, is unknown. At the end of World War II, the Nazis managed to find the Mother Box entrusted to mankind in an Italian monastery. The Nazis arranged to send it to Hitler, but the Box was intercepted by the Allies and reached the United States in 1944, safeguarded under the United States Department of Defense.
They conducted numerous studies but were unable to date it due to its age. The Box was then shelved in an archive, up until when it was then sent to Doctor Silas Stone, who recognized it as a perpetual energy matrix. Silas' studies of the Box led him to theorize it as the key to unlimited energy, paving the way for advancements in scientific research such as cellular regeneration, but he ultimately concluded that it was too volatile a technology to use.
Creation of Cyborg
In 2015, 33 years later, Silas Stone attempted to help his critically injured son, Victor Stone. However, nothing Silas attempted worked to stabilize his son's condition. As he created a video log describing his failed attempts, including attempts to use the Mother Box in the government's possession, the Box activated suddenly, pulsating with energy as it began to move towards Victor as though it were alive.
Upon reaching Victor, the box began repairing his body, fusing him with nearby technology as Victor screamed in agony. The video log abruptly ended with Silas hastily shutting it off.Footage of his revival would later be obtained from S.T.A.R. Labs' database by Lex Luthor.
The Death of Superman
Following the death of Superman, a projection of Steppenwolf was seen surrounded by three Mother Boxes, standing before Lex Luthor as he was about to be arrested. Around the same time, one Mother Box activated, described by Victor Stone as being 'lit up like Christmas'.
- "Muscles. Coordination. Basic cellular integrity. A human being can only absorb so much.The Mother Box was designed to reshape a planet. But what if you were stronger than a planet? If your cells were lying dormant, but incapable of decay? A boost from the Mother Box-"
"Could bring him back to life."
- ―Batman and the Flash[src]
During Steppenwolf's return to Earth, Batman concocted a plan to use a Mother Box's energy to resurrect the deceased Superman, based on its ability to do so with Cyborg, as the newly formed Justice League needed him to help fight off Steppenwolf and his army.
However, Wonder Woman and Aquaman were skeptical of this, but Bruce relented (privately forming a contingency plan should anything go wrong). They took the Mother Box to the Genesis Chamber in Scout Ship 0344, where they placed Clark's body in the Chamber's pool. Unfortunately, the Chamber's circuitry was fried by Lex Luthor during his creation of Doomsday. Cyborg explained that they'd need a massive surge of energy to activate the Box and revive Superman successfully, and Flash decided to utilize his speed to create an electric charge to jumpstart the Box to work in tandem with the Chamber's pool. Barry then ran to a separate area of the ship, and Cyborg started a countdown, telling Barry he'd need to time his shock at the exact moment the Box touched the water.
The process was successful and Clark was resurrected, although the revival left him disoriented and resulted in him attacking the League. Lois Lane arrived on the scene soon to help him regain his memories and flew away to his home and reunited with his mother. After Clark recovered, he helped the Justice League defeat Steppenwolf.
This article section is incomplete and requires expansion.
- Self-Sentience: The Mother Boxes are sentient to a degree and capable of even "feeling" emotions, such as fear when they 'sensed' Superman. Upon the conclusion of their battle with Doomsday, the shockwave from Superman's death cries jolted two of the Mother Boxes into temporarily awakening and the other to remain awake and communicate this to Steppenwolf. When Cyborg fused with the Unity, the Mother Boxes realized his intent and took on a set of forms closest to him in order to dissuade the hero from stopping the Unity.
- Biological manipulation: Mother Boxes are able to manipulate life on a cellular level, including augmentations of biological functions, by utilizing a unique energy field. One such Box was able to resurrect the deceased Superman when combined with a Kryptonian Genesis Chamber in Scout Ship 0344 and a massive electrical charge from the Flash. A Mother Box was also able to stabilize the critical condition of Victor Stone, reviving him from near-death.
- Biomechatronic enhancement: While reviving Victor Stone, a Mother Box was able to generate mechatronic body parts in place of the ones he had lost, as seen on the metahuman archive files collected by Lex Luthor. This process is seen to be extremely painful, as it grafts organic and inorganic parts together, effectively creating a cyborg.
- Cellular regeneration: The Box's energy can heal and restore lifeforms. After Superman's resurrection, the large hole in his chest caused by Doomsday had completely healed.
- Boom Tube generation: Mother Boxes are able to open extra-dimensional point-to-point cylindrical portals for transportation used by the New Gods of Apokolips. This was used by Steppenwolf to arrive on Themyscira.
- Terraformation: The Mother Boxes' original purpose was to use their immense power to reshape a planet into another version of Apokolips. When three Mother Boxes are united, the combined energy would've terraformed Earth, had it not been for Zeus' intervention. The explosion of pure energy generated by the boxes successfully synchronizing is enough to destroy all in its path including super-powered beings, even the likes of Superman, due to its matter manipulating properties.
- Radiation metabolization: According to Cyborg, the highly radioactive base of Steppenwolf was no longer radioactive because the Mother Boxes harvested all of the radiation to built his base and its fortifications.
- Communication with Apokolips: The Mother Boxes also served as a means to establish a communication method for Steppenwolf to inform and receive information directly from Apokolips.
Behind the scenes
- "The Mother Boxes were created on Steppenwolf's home planet. They are instruments that can convert energy to create or reform matter. Then, if you put the three Mother Boxes together, they become an unstoppable force, the Unity, which Steppenwolf uses to conquer planets."
- ―Justice League producer Charles Roven[src]
- The U.S. government's Mother Box has a code name: "US GOV Object 6-19-82". The numbers can be interpreted as "June 1982", the month of publication of Cyborg's origin story in Tales of the New Teen Titans #1.
- Director David Ayer revealed that the original script for Suicide Squad involved Enchantress under the control of a Mother Box with Steppenwolf prepping an invasion with a Boom Tube. 
- According to the first main script of the movie, the Mother Box on Themyscira had to activate in the post-credit scene. Assumingly, it would happen after the death of Ares, the last Old God.
- Batman v Superman's Cyborg scene explained - Entertainment Weekly
- Terrio, Chris, Beall, Will (writers) & Snyder, Zack (writer and director) (March 18, 2021). Zack Snyder's Justice League.
- Etta's Mission
- Terrio, Chris, Whedon, Joss (writers) & Snyder, Zack (director) (November 17, 2017). Justice League.
- Goyer, David S., Terrio, Chris (writers) & Snyder, Zack (director) (March 25, 2016). Batman v Superman: Dawn of Justice.
- Steppenwolf Was Originally a Huge Part of Suicide Squad