- "You're quick-witted, Kara Zor-El, but not quick enough. My odds of passing their test are about to get even better."
- ―Dev-Em to Kara Zor-El after killing her boyfriend Kell-Ur[src]
While participating in a physicality test, Dev-Em killed team member Kell-Ur, in an attempt to better his odds of passing the test. He then assaulted Kara Zor-El, after she learned of his actions. For his crimes, he was put in front of the Kryptonian Law Council, who sentenced him to death. Upon objection by the other ranking members of the council, the decision was made for Dev-Em to instead remain in custody.
He later escaped, and sneaked onto Scout Ship 0344. While the crew members were in cryosleep, Dev-Em awakened and killed all of them except for Kara Zor-El, and changed the ship's course to head for Earth. After Kara awakened, the two of them fought, while the ship crash landed into Earth's atmosphere. Kara attempted to control the ship, but it crashed in Ellesmere Island, Canada, leaving the fates of both of them unknown.
Kryptonian physicality test
- "We're simulating the harsh and unpredictable conditions Explorer's Guild members potentially encounter, Kell. There's no telling what we could find before the terraforming begins. Or what might find us."
- ―Kara Zor-El telling Kell-Ur why their suits are necessary.[src]
Dev-Em was born on the distant planet Krypton around 16,000 B.C. At a young age, he joined Krypton's terraforming project. While on the deadly physical test that would determine the best candidates to go on to space colonization missions, Dev-Em attempted to get an advantage over the other candidates. He killed his main competition, Kell-Ur, who was the lover of Kara Zor-El. Upon witnessing his death, Kara beat Dev-Em in combat and subdued him.
Trial at the Kryptonian Law Council
- "Accused Dev-Em, after five weeks of deliberation, we find you guilty of assaulting Kara Zor-El and murdering Kell-Ur. Krypton's first murder in a thousand years. Your blatant disregard for the life of your fellow students is troublesome. As a result of your actions, I hereby recommend to my fellow council members death--"
- "No, Dar-Enx! We are not barbaric, like the Thanagarians! Our laws are not "an eye for an eye, a life for a life"!"
- —Dar-Enx and Dug-Les debate the sentencing of Dev-Em[src]
Five weeks after the murder of Kell-Ur, Dev-Em was put on trial in front of the Kryptonian Law Council for Krypton's first murder in centuries. Dar-Enx recommends that Dev-Em be given the death sentence, but the rest of the council shows opposition, not wanting to be "barbaric" like the Thanagarians. Dar-Enx then rules that until the Council can agree on Dev-Em's fate, he should then be sent to prison and remain within the council's custody.
Sometime later, Dev-Em was freed with the aid of Dug-Les and Syra Ten-Ar of the Kryptonian Law Council, who had earlier brought the first opposition of killing Dev-Em. Rather than approve of an action that they saw as a betrayal of Krypton's values, the two members surmised it would be better to free him and aid him in sneaking aboard Scout Ship 0344, where he would end up far away from Krypton's gaze. In the meantime, two Kryptonian prison guards determined that Krypton's first murder in centuries should also quickly be followed by its first execution. They approached Dev-Em's cell and prepared to carry out the execution before realizing that Dev-Em had somehow escaped.
Fight on Scout Ship 0344
- "You've been asleep for a long time but I'm glad you're awake now. Hello, Kara."
- ―Dev-Em to Kara Zor-El after she awakens.[src]
While all the crew are in cryosleep, Dev-Em awakes them before killing them afterwards and changing course for Earth. Kara awakens and discovers the bodies of the crew members and battles Dev-Em as the ship approaches Earth. Kara attempts to turn the course of the ship, but it crash lands into Ellesmere Island, Canada, leaving the fate of Kara and Dev-Em unknown.
Centuries after his defeat, another male member of his house would come to share his name. By pure circumstance, this descendant would commit to a similar path as his ancestor, breaking the laws of Krypton in brutal fashion, put to trial and imprisoned by the Kryptonian Council rather than killed, before eventually finding their way to Earth where they would face defeat due to the actions of yet another member of the House of El.
Dev-Em was ego-maniacal, obsessed with controlling Krypton's future for his own benefit. He had a distaste for authority, ignoring the orders of Kara Zor-El.
Powers and abilities
- Kryptonian physiology: As a Kryptonian, Dev-Em possesses superhuman abilities. On a planet near a red star, Dev-Em would have physical attributes nearly identical to those of humans, but while on a planet near a yellow star, he is granted many new abilities and powers that surpass the capabilities of humans.
- Superhuman strength: Dev-Em has an incredible amount of strength which is nearly incalculable, and can carry and apply over millions of tons of force. However, his weakness Kryptonite can lower his strength when exposed to him.
- Nigh-invulnerability: Dev-Em's body is nearly indestructible, and he is immune to things such as intense heat. However, Kryptonite can make her body less indestructible.
- Superhuman speed: Dev-Em could run and fly at tremendous speeds.
- Superhuman reflexes: His speed also extends to her reflexes.
- Superhuman stamina: Dev-Em could be able to never seem to grow tired, and could survive flying at high speeds in outer space and underwater.
- Regenerative healing factor: When exposed to radiation of a yellow sun, he could heal at incredible rates.
- Skilled combatant: Dev-Em is a highly skilled hand-to-hand combatant.
Behind the scenes
- In DC Comics, Dev-Em was a juvenile delinquent on the planet Krypton who became imprisoned in the Phantom Zone. Eventually, he escaped during the 30th Century, where he turned over and became a teenage superhero.
- Another character named Dev-Em appeared in Man of Steel as one of the soldiers loyal to General Dru-Zod and his Sword of Rao movement.