The Fallen One possesses the 'Power Primordial', like all other Elders. The Power Primordial' is residual energy left over from the Big Bang that created the current Marvel Universe. The circumstances in which the various Elders each gained some of this energy are yet to be revealed. While the energy itself is vast, it takes years of intensive training to purposely channel the energy to grant each of the Elders the various superhuman physical, mental, or energy manipulative capabilities that they possess. Each Elder has purposely channeled the Power Primordial to grant them greater abilities in some areas than in others. This renders the Power Primordial similar to the cosmic energy housed in the bodies of the Eternals. While all of the other Elders have devoted some of this energy into developing their intellect and to manipulate energy for various uses, the Fallen One has channeled it entirely to the development of his physical form.
The Fallen one possesses vast physical strength, the limits of which are virtually unknown. On his own, he is capable of lifting at least 100 tons. However, his strength was increased to much higher levels while in possession of the 'Power Gem', one of the Infinity Gems. While in possession of the gem, he could lift far in excess of 100 tons. He once destroyed an entire planet by delivering a single punch after jumping several thousand feet into the air.
In spite of his great size, the Fallen One is able to run and move at speeds that are beyond the natural physical limits of the finest human athlete.
The Fallen One's highly advanced musculature is considerably more efficient than the musculature of a human being, producing far fewer fatigue toxins during physical activity. On his own, the Fallen One can exert himself physically for at least several days before the build-up of fatigue toxins in his blood begins to impair him. While in possession of the Power Gem, the efficiency of his muscles was increased to the point that they produced no fatigue toxins. As a result, he possessed limitless superhuman stamina.
Despite his tremendous size, the Fallen One's agility, balance, and coordination are enhanced to levels beyond those attainable for even the finest human athlete.
Much like his agility, his reflexes are superior to those of the finest human athlete, despite his great size and bulk.
The Fallen One's body is highly resistant to physical injury. He can easily withstand high caliber machine gun shells, exposure to temperature extremes, falls from tremendous heights, and energy blasts from the likes of the Silver Surfer without sustaining injury. He is also fully capable of surviving in the vacuum of deep space indefinitely.
Like all the other Elders, Death itself has banned him from entering its realm. As a result, he is truly immortal. He is immune to the effects of aging and disease and cannot be killed. Even though it is possible to injure him, no injury, no matter the severity, can prevent him from recovering fully. Prior to Death's banishment, he was still immune to aging and disease. He also did not require air, food, or water because the Power Primordial was all that sustained him. However, despite his high resistance to injury, it was possible for him to be killed. Also, prior to Death's banishment, the Fallen One's endless life was sustained through the pursuit of his obsession with improving his physical capabilities, fighting skills, and challenging fighters from all over the universe.
The Fallen One claims he has mastered countless styles of combat and martial arts from all over the universe. However, he seems to stick to boxing for his challenges. Nevertheless, he is a formidable combatant.