F.0-X alias Fox, was the first prototype of the F-Series made in the HNCs "The Agency" facility.
Since they used different procedures to modify the human psychology, the Subject showed some abnormal results. to increase the effectiveness, the subjects "humanity" had to be decreased, human thoughts and actions would lead to a failure and loss of control over the subject.
F.0-X's humanity and empathy were removed entirely, which results into a state of psychosis which causes him to be loyal until his death, the process has granted him four times the strength of a normal human as well as giving him heightened speed and intelligence.
Downsides of this process include the lack of care regarding his own life also F.0-X's body needs to be "cooled down" by injecting strong sedatives, if these sedatives are not injected, F.0-X will continue to fight harder, faster until his bodily functions stop and he drops dead.