Aaron Keener is the final antagonist in the Ubisoft game Tom Clancy's The Division.
Information on Keener given in the game indicates that Keener considers himself of a higher intelligence than anyone else around him, and that he used his intelligence to make his living as a futures trader. He was chosen to become part of the Strategic Homeland Division for this very reason, as Keener's sharp intellect and action-oriented nature would be vital traits in the event of a mass catastrophe on US soil.
The First Wave
During the initial outbreak of the Dollar Flu on New York City, Keener was activated with the First Wave of Division agents in order to try and restore order to the city. The issue was that the First Wave wasn't enough to curb the outbreak of violence, looting, and killing that would become New York during the initial weeks of the outbreak. While at first only forced to contend with various groups of rioters, the situation took a drastic turn when a majority of the inmates of the Rikers Island correctional facility managed to secure a barge and escape into Manhattan coupled with the formation of what became known as "The Dark Zone", an area of central Manhattan that the government had deemed out of their hands and sealed from the city.
It was from the Dark Zone that Keener had rescued a group of civilians. As he was attempting to lead them to safety, Keener was ambushed by a group of Rikers inmates. Sheltering the civilians inside an abandoned apartment building, Keener desperately tried to radio to the nearest friendly forces for backup and evacuation for the civilians. When the friendlies replied they couldn't afford to spare any forces for the pickup, a Riker molotov cocktail crashed through the window and into the apartment. Keener was the only survivor.
Shaken by what had happened, Keener became a ghost in the crumbling city. The First Wave of the Division agents vanished while the city was overrun by what soon became the forces of the Rioters, Rikers, Cleaners, and the Last Man Battalion.
The Second Wave
When the Second Wave was activated, Manhattan was only barely held by the Federal Joint Task Force. Rioters were overrunning Brooklyn, and the JTF had suffered enormous casualties both from the Dollar Flu and from opposing forces. Holding Brooklyn and moving into Manhattan, the Second Wave was soon confronted with evidence that the majority of First Wave agents had been killed by the various factions trying to control Manhattan.
It was during a Division raid on the New York Police Academy that the truth was found. The First Wave hadn't been wiped out. It had simply found a new force to follow. At Keener's urging, multiple First Wave agents fell in with the Last Man Battalion in East Manhattan and hunted down their remaining First Wave comrades. While the discovery sent shock waves through the Second Wave and JTF, Keener was focused on ensuring he was part of the superior force in Manhattan. Through with government oversight and the Federal government's refusal to do what he felt was "necessary", Keener found that the Last Man Battalion's ideals of peace at any cost meshed far more effectively with his worldview.
Commanding his turned First Wave agents to gather up anything of value related to the Dollar Flu and to combat the efforts of the Second Wave in New York City, Keener realized the power at his disposal when he managed to gain control of the protein "printer" used by Gordon Amherst to create the Dollar Flu, and the unwilling services of Dr. Vitaly Tchernenko. By the time the Second Wave agents regain control of the neighborhoods of Manhattan and eliminate the LMB as an effective force, Keener is gone.
His fate is currently unknown.
Keener is at best a clinical sociopath. Able to easily manipulate those around him into doing what he wants them and always preferring to be on the most successful side of a situation. His desertion of the Division, followed by leaving the LMB to be destroyed, show that Keener is only loyal to his own ambitions. This is exemplified in one of the game's ECHO logs in the United Nations building, where the footage shows Keener eliminating members of the LMB and ordering two rogue agents to remain behind to stall the player long enough to allow Keener to escape New York's quarantine zone and take Tchernenko with him.
He is also willing to try to manipulate the same agent who has been hounding him across New York City. In the final ECHO log involving Keener, he mentions that the agent is as efficient and willing to do what is necessary as Keener, and that if the agent is so willing, then perhaps they would be willing to join with Keener.