Superhumans have almost always existed among the human population. They are genetic mutations created by exposure to various forms of radiation, both naturally occurring and man-made. The rise of the use of radiation has led to a rise in the number of superhumans found throughout the world, but they still represent a very small minority, which is how the humans are able to suppress them as a group. Some are born free and captured after the authorities have been alerted to their existence. Others were unlucky enough to be born into the system to a previously imprisoned super. Child supers may be drafted into the Poltergeist program, which trains them from young ages for a future in the Ghost Corps.

Synthetic superhumans are a new type, as recent as 2011, when the first successful experiments were completed. Some have theorized that these individuals were born with the potential to be supers, but the genes remained unexpressed; this has yet to be proven one way or the other. Synthetics come from various backgrounds: some were prisoners on death row whose "deaths" were publicly faked, and who were experimented on against their will; some were volunteers from different government branches, including military; some were civilians who were invited into the program for particular reasons. Regardless of how they came to be test subjects, once the experiments resulted in a super, all became relegated to the Ghost Corps and given the same treatment as any other.

Powers range the gamut, from telepathy to super strength, from pyrokinesis to metal skin. Supers can have up to three powers that fall into primary or secondary categories. Primary powers are stronger and more refined than their secondary counterparts. Secondary powers are weaker or more subtle. Sometimes a super's powers are a linked set that make sense together, but not always. When the powers are not linked, it's most likely that one will be a primary power, and the other one or two will be secondary.

Individuals have different levels of control, and different capabilities within their own blanket power; for example, one healer might be able to heal only themselves, while another can close any open wound, or a third could only cure acquired diseases, and so on. In Ghost Corps, most supers are expected to have a certain level of control over their powers, save for newly minted synthetics, who are given some leeway as they adjusted to their recently acquired abilities and lifestyle.

The agency has divided powers into six broad categories, with the last category being the broadest of all. Sometimes the reason a super is labeled as one, when their ability could fall into more than one, is the difference in the training they have received. They are:
  • Tank: capable of withstanding or mitigating a lot of damage, typically more than they are capable of dealing, though that is not a hard and fast rule. In the case of high damage dealers, what separates them from the "damage" class is the training they receive and what power(s) are primary or secondary for them.
  • Healer: a rarer ability, and therefore coveted for the program. Some healers are conscripted for Ghost Corps against their will, and scientists prefer to create this type over all others. The healers recruited for Ghost Corps must be capable of healing others, not just themselves, and healing must be their primary attribute in order to qualify for this position. Each team can only have one healer.
  • Damage: covers a wide array of powers that can be used against people or objects, ranged or melee distance.
  • Infiltration: anything that can be used to blend in with a crowd or the background, or to get in and out. Infiltrators are physically involved in that they get up close and personal with the mission, and may have to kill someone, even if their powers are not offensive in nature. Examples include, but are by no means limited to, shapeshifting, invisibility, and illusions.
  • Surveillance: the spies of the group. They are responsible for compiling data before and during missions, at base or on the field, usually from a distance, but sometimes up close, depending on the nature of their power and the needs of the mission. Even if they don't get involved in combat often, they are still trained to fight. Examples include, but are by no means limited to, telepathy, sight enhancements, and astral projection.
  • Wildcard: the junk drawer category. Anything that, for whatever reason, does not fit into one of the above categories is considered a wildcard. They can be trained a number of ways, or have trained in multiple categories, or there just wasn't room in another spot for them.