4NG3L0 was created by sith alchemists with the intention of creating a low-intelligence species that would be smart enough to take orders but dumb enough to not question them, and used force lightning instinctively, circumventing the need for training. Rather than being born, he was extracted from a bacta tank. The experiment was a partial success, for he attacks using force lightning, but overall failure due to being uncontrollable in laboratory conditions. Another side effect was the ability to channel his negative emotions and memories into a powerful wave of force fear. In addition, he can sense a person's alignment, supposedly by smell. Through the atrocities performed on him early in life, Angelo developed an innate hatred of the sith, and desires to punish anyone with a red lightsaber.
After escaping euthanasia at the laboratory of his origin, "Angelo", as he mispronounces his serial number, stowed away aboard a cargo ship and through similar methods, planet-hopped around the galaxy for a while, all the time absorbing as much as he could about "sentient" culture and behavior.