Origin  

Malcolm Monroe and his twin sister Jenny were the offspring of Flashback, a Canadian criminal with the mutant ability to control duplicates of himself pulled from alternate futures. Both he and Jenny also developed the ability to create and control temporal duplicates of themselves. However, their relationship with their biological father was a strained one. With liberal use of his and his sister's temporal duplicates, Malcolm set up a comfortable lifestyle for himself with Jenny in a secluded mansion in Alberta, Canada. 

Creation  

Malcolm Monroe was created by Jonathan Hickman in Secret Warriors. The character was first mentioned by name and description in the backmatter of the first issue but did not actually appear until much later in the series. When he appeared in issue #24, he was illustrated by artist David Marquez. 

Major Story Arcs  

Wheels Within Wheels  

Unknown to Malcolm or his sister, they were both on Nick Fury's Caterpillar list, a secret record of superhumans who had not yet been discovered and recruited by other parties. One day, Mikel Fury showed up with Carlos Ayala to recruited the twins for his Secret Warriors team. They immediately refused. Malcolm had a good life and saw no reason to leave it. However, Mikel exposed the criminal activities Malcolm had been committing in secret from Jenny to support their lifestyle and claimed that was a matter he could sort out for them. Malcolm tried to deny the truth but was unable to convince anyone. Surprised by his secret, Jenny reluctantly agreed for the both of them. 
 

Malcolm, with his sister, became a member of the Secret Warriors' Team Gray, led by Mikel Fury. Along with the rest of that team, he was tasked with surveillance and other intelligence gathering on the reclusive organization called Leviathan. It was a largely uneventful assignment. Leviathan had seemingly gone dark for decades, leaving Team Gray with very little activity to go after. This changed when Magadan succeeded in awakening Leviathan's leader, Orion. It was not long after that Leviathan activity spiked and a war began with HYDRA. Team Gray's job became busier. 
 
In the months that followed, Nick Fury's secret war that pitted the Secret Warriors between Leviathan and HYDRA heated up. Losses were heavy on all sides, and a civil war had broken out inside of HYDRA. Team Gray was sent in to take out the Hive's HYDRA stronghold. The mission went bad and the entire team, including Malcolm, lost their lives while completing the mission objective. 

Powers and Abilities  

Malcolm Monroe has the ability to produce temporal duplicates of himself that obey his wishes. This ability seems to be identical to his father's, but it has not been fully explored. The fact that Malcolm and his sister have gone seemingly unnoticed by the X-Men draws into question whether this is actually a mutant ability. 
 
As a member of the Secret Warriors, Malcolm has presumably undergone intensive training in combat and espionage skills.