Krall is the main antagonist of the science-fiction film Star Trek Beyond. He is a warlord who is opposed to the ideology of the United Federation of Planets, believing that seeking peaceful coexistence with other races is inherently wrong. Ironically, however, Krall used to be a Starfleet captain, sworn to uphold such ideals. He was portrayed by Idris Elba.
The being known as Krall was once a Human known by the name Balthazar Edison. During the 22nd century, he served in United Earth's Military Assault Command Operations. He had a distinguished career, fighting on behalf of Humanity during the Xindi and Romulan wars.
After the Federation was founded in 2161, MACO was disbanded and Edison became a Starfleet officer, being given captaincy of the USS Franklin. However, Edison secretly resented this promotion; having been born into a life of conflict, he viewed the Federation and its ideal of peaceful diplomacy with other races as an affront to everything he had fought for. Despite this, he led his ship and crew on many missions for Starfleet using his tactical training and knowledge of advanced combat to successfully complete those missions.
In 2164, the Franklin was displaced by a wormhole while inside the Gagarin Radiation Belt. The ship crashed on the distant planet Altamid, with Edison, Anderson Le, and Jessica Wolff as the only survivors. Edison sent out a distress call but, receiving no response, came to believe that he had been abandoned by the Federation. As his resentment festered into violent hatred, Edison resolved to destroy the Federation and prove that peaceful coexistence led only to weakness. It was not until 2255 that Starfleet had him formally declared missing in action.
On Altamid, Edison found technology left behind by a previous civilization, including Swarm ships, a drone workforce, and an energy transference process that allowed him to "drain" other individuals to prolong his own life. Using their newly-acquired Swarm, Edison, Le, and Wolff captured scores of alien ships and drained their crews to survive, which also mutated their biology to resemble that of their victims. In time, Edison became "Krall", suppressing much of his Human identity and ceasing to speak in English.
Krall learned that the natives of Altamid once created a super-weapon called the Abronath, which they had split in two and launched into space. He located one piece after decades of work, but not the other.
Destroying the Enterprise
In 2263, Krall discovered from Starfleet logs, accessed through a captured Magellan probe, that the second piece of the Abronath had been placed into storage on the USS Enterprise. He dispatched Kalara, to lure the Enterprise to him. Upon the arrival of the Enterprise at Altamid, Krall attacked with his Swarm. He destroyed the Enterprise, captured most of the crew, and eventually coerced Ensign Syl into relinquishing the second Abronath piece. His weapon complete, Krall departed Altamid with his Swarm to wipe out all life from the nearby Starbase Yorktown, whose multicultural population he saw as the epitome of the Federation's degeneracy.
Attack on Yorktown
Krall's Swarm overwhelmed Yorktown's defenses and was on the verge of breaking inside when he was engaged by the Franklin, commanded by the Enterprise's former captain, Captain James T. Kirk. The Franklin, and later the starbase, used a VHF radio broadcast to disrupt the Swarm's internal communications network and destroyed most of the craft. Krall managed to enter Yorktown, but the Franklin physically stopped his ship short of his destination.
Having drained many Enterprise crew members before and after the battle, Krall had regained much of his Human physiology and was thus able to disguise himself as a Starfleet officer. This allowed him to make his way, unimpeded, to the central atmospheric processor on Yorktown, where the Abronath's effects would be disseminated throughout the station. He was intercepted by Kirk, and the two fought while Montgomery Scott redirected the processor to vent into space; Kirk then ejected both Krall and the Abronath out of Yorktown. Krall died upon exposure to hard vacuum, then the Abronath consumed his body.