Mason was born in a small town in Arkansas to a regular family. The family had two older sons, that showed no signs of any powers, or abnormalness, but when Mason was born their lives turned upside down. From the moment he was born Mason was able to feel the emotions of those that were around him, as shown when he never stopped crying from the time he came home from the hospital until he turned one when he was somewhat able to subdue the emotions. Sometimes the emotions would still come through and Mason would have tantrums at random points without provocation. Around the time that he was seven, Mason began telling people what they were feeling and in the 1950's this was believed as a sign of craziness. Mason's parent's sent him to an asylum where he was put into solitary confinement, for his entire eleven year stay.
But that time alone gave Mason what he needed most time to practice. Mason learned how to somewhat control the flow of emotions within himself, he was able to set up a "wall" of his own emotions to keep the other ones centered and in control. Mason kept himself calm and controlled, until he formulated a plan to escape the asylum. One day when the guards came to feed him, Mason used the emotions welled up inside of him, to cause the guards to die from the emotional overload. Mason the ran from the room using the emotions to cause the other patients to create an uproar. Mason then jumped through one of the windows and landed on the ground outside. Mason ran to the next town and broke loose from the straight jacket. He then booked a ticket on the next bus to New York, and enlisted in the army. The next month Mason was in Vietnam, fighting and quickly moving through the country and killing many civilians. One day he lost control he saw one of his comrades brutally kill a small child for no reason. This caused part of Mason's "wall" to crumble, allowing for the emotions to completely over run his body and mind. Mason then took down his entire company, disarming and killing over twenty men in less than a minutes time.
The next morning Mason found himself in a cell at the base, awaiting execution from a firing squad. But before they killed him, Mason was approached by a man that was creating an undercover force for people with special abilities. Mason however declined, and was taken to the firing squad, they fired but when the bullets hit Mason didn't die, the squad was in complete shock, which allowed Mason to escape. He headed to Tibet and began meditating at one of the temples, learning how to better control the adrenaline that flowed within his body. However he was not able to gather the adrenaline in greater amounts at will. When he was enraged or feeling another strong emotion he was capable of increasing his strength and agility.
One day while he was meditating, Mason accidentally astral projected in one instance, and observed the Cataclysm and the destruction of New York City. When he returned to his body he found the wall to his left was completely obliterated, from a punch by him. The next day a helicopter arrived, and a man stepped out offering him to join in the recreation of the Avengers. Mason agreed to join because he had more control than he did the previous time they tried to recruit him, allowing him to turn off his powers completely, finally giving him some peace and quiet.