Cain Marko may be a big jerk, but he has had a rough life. At an early age, Cain’s mother passed away. Cain had to deal not only with the death of his mother, but he had a tumultuous, abusive relationship with his father. Dr. Kurt Marko psychologically and physically abused Cain from an early age, and even on into Kurt Marko’s marriage to Sharon Xavier, widowed mother of Professor Charles Xavier. No doubt, the death of his mother took a toll on Cain, and coupled with his father’s abuse, was already damaging his fragile psyche. The fragility of Cain Marko’s mind was put to the test even more when his father remarried. From a developmental point of view, stepfamilies can put a strain on everybody involved, and this strain can lead to adverse behavior. In the case of the Marko/Xavier family union, this strain proved too much for Cain to take. The Marko/Xavier stepfamily is what is known as a blended/complex stepfamily. In this type of stepfamily, both parents bring children from previous marriages to live in the newly formed stepfamily. This can make adjustment difficult, which is exacerbated by the age of the child, in this case adolescence. In the case of Cain, his father heavily favored the gentler, soft spoken Charles, over him. No doubt Cain was abrasive due to the death of his mother and the abuse endured from his father. Throughout Cain’s life, he had been in pain, so Kurt Marko’s favoring of his new stepbrother Charles was nothing new. It was just another wound inflicted by his father. The death of his mother, the physical and psychological abuse by his father, and the favoritism shown to his new stepbrother finally pushed Cain over the edge. Thus, he began bullying Charles. After all, he was taught very well by his father. After the death of his father in a lab fire that was caused by Cain himself (by accident), and the death of Charles’ mother Sharon from a broken heart (Kurt Marko abused Sharon as well), Cain regarded Charles as his enemy. While fighting in the Korean War, Cain and Charles stumbled upon the ancient temple of Cyttorak, which housed the powerful Ruby of Cyttorak. Upon picking it up and reciting the inscription on it, Cain was transformed into a Juggernaut.
Thus is the sad tale of Cain Marko. Cain was never able to properly deal with the death of his mother due to the years of abuse he endured by his father. This inability to deal with the loss of his mother, coupled with the physical and psychological abuse by his father, pushed Cain over the edge. As an adolescent, Cain manifested his anger and hostility in the form of bullying his stepbrother Charles. The adjustment of having a new stepmother and stepbrother took its toll as well. One can safely say that Cain never really hated his stepbrother, but he hated the fact that he could never reconcile the emotions that accompany the loss of a parent and years of abuse. The tragedy in his life was the real unstoppable juggernaut. Later in Cain’s life, he has shown that he could be an asset for good; on some occasions joining the X-Men and Thunderbolts. One can only wonder just how much the relationship between Cain and Charles, and Cain’s life as a whole, would have differed if he was able to properly deal with the tragic events in his life.