According to Smith, when he was 14 years old, he woke up one morning and noticed he could "move, hear, see and do noticeably better than the night before." Every day after that, his powers grew greater and greater until he realized that he "had super powers like a comic-book character." His father ran a small mob at the time, and a rival gang killed him and took over the gang. Smith took revenge on everyone involved in the murder of his father, ripping out their spines, one by one. He then turned his father's gang into a criminal organization that took over the city.
Some time after this, he met Helspont and the two became partners in trying to take over the world. Slaughterhouse Smith knew that helping Helspont meant betraying his race and he was perfectly fine with it. He had never felt like he was part of the human race to begin with, so killing everyone to make way for the Daemonites was not a problem.
Slaughterhouse Smith is a post-human with the ability to shoot blasts of energy from his eyes and hands. He can also cover his hands in energy (without blasting it) to give himself an incredibly powerful punch. Along with his energy powers, Smith is stronger, faster and has better senses than any normal human.