John White
The Beast (formerly known as John White) was once a former NSA agent who assigned to patrol Empire City and destroy the Ray Sphere. However, the Ray Sphere killed him when it was destroyed by Cole Macgrath. Eventually, his subconscious was reborn as "The Beast", revived him as a conduit with immense power that capable to transform into a humanoid giant monster out of magma and controlling Ray Sphere energy to awakening powers within individuals with conduit gene.
Pre-Game
Not much is known about background or history of the man that would became The Beast, John White, other than he's never been married and he has an extreme dislike for FBI agents before the event of inFamous. At some point in his life, he got a job as an undercover agent in the NSA, and was given the assignment of infiltrating the secret organization known as the First Sons along with agent Lucy Kuo, chosen due to their unique genetic code, possessing the Conduit gene. Kuo was stationed in New Marais while John was sent to Empire City. He also assigned to collect information on Kessler as well. He does his best, leaving dead drops for his handlers to find in the city.
John first met up with a woman named Jane, and was told that he was a low-level mentalist. He was instructed to meet at a secluded place, but upon arrival was ambushed. He infiltrated the First Sons after passing their initiation. Stationed at Empire City's chapter of the organization, John's primary task was to know what the First Sons have been doing that can be considered as a national threat. Able to get himself close enough to the leader of the group, Kessler, John was able to learn of the device called the Ray Sphere, and its capabilities of giving out powers to those who possessed the Conduit gene. John would later get promoted, able to know Kessler close enough, and was also given higher-tier missions, high enough for him to grasp the Ray Sphere. He would also be given simpler missions like escorting one of their scientists, Sasha, to an undisclosed location somewhere in the Warren. During his time, he'd relay the information to his associates at New Marais, informing them of his latest findings.
Through his findings, he was able to learn that the First Sons do possess materials that can label them as a national threat, with several experiments that involved Ray Field energy, which resulted in the deaths and abnormalities of subjects, both human and animal alike. He would also become enraged due to the lack of proper communications with their head branch at the NSA, making him lose confidence and trust for his employer. After some point, specifically on the day of the blast, John has learned that Kessler has scheduled a delivery for the Ray Sphere as a package, with Cole MacGrath as the specific courier. Learning his John was immediately chases and trying to stop Cole from activating the Ray Sphere, but unfortunately missed him because of a red light.
inFAMOUS
John White appears assisting Cole in the last few missions of the game, after the Ray Sphere is destroyed/activated John is sucked into it and disappears. The alternate future version of The Beast is shown in Kessler's future vision of how he wrecked the world. This is the very reason Kesser travels back in time to fix this.
inFAMOUS 2
The Beast is the main antagonist of inFamous 2. His true identity is revealed to be John White, whom Cole helped out in the first game trying to destroy the Ray Sphere. It turns out that the energy in the Ray Sphere took over John's
The Beast
body after he is sucked into a vortex of it. He literally pulls himself back together as Cole's boat is leaving for New Marais, and destroys Empire City. He then travels down the coast towards New Marais and reveals to Cole that he isn't commiting mass murder. He's activating Conduits in the cities he destroys, but killing all non-Conduits in the process.
In the canon (good) ending, The Beast is defeated when Cole uses the Ray Field Inhibitor, killing the Beast, himself and every other Conduit.
Evil Ending
Cole joins The Beast and Kuo and works to awaken the conduits thus curing them of the plague. The Beast gets tired after Cole kills Nix and Zeke so The Beast gives Cole his powers and lets him complete the mission to awaken the conduits and cure them of the plague, while destroying all the life that does not have the conduit gene.
Possible discrepancy - A Second Beast?
Kessler's use of time-travel raises the question of whether John White was also the Beast of his original timeline. John White in the first game was transformed by events whose frame was shaped by Kessler's meddling in the new timeline. While it is possible the John White of the original timeline (if there was one, since Kessler had a century to alter known history) was the man who became the Beast through existing Ray Sphere experiments, the possibilities exist that the Beast of the original timeline was never (or has yet to be) transformed, or even that the original Beast could one day duplicate Kessler's one-way time door.
However, the possibility that John White and the Beast in Kessler's timeline was one in the same was likely, as hinted by dead drops that Cole later found in Infamous 2.