Jacklyn Mitchell is the youngest daughter of FBI Frank Mitchell. One day while Nicole (Jacklyn's older sister) were playing hide and seek, Roman Von Drake entered the Mitchell family home. Nicole could only watch from her hiding place as the man slit her father's throat and took her baby sister away. Jacklyn would be raised by Von Drake to be his master assassin and later serve as his lover as well. When Razor, a now adult Nicole Mitchell, began interfering in his operations he dispatched Stryke to bring her to him. It was Jacklyn who first realized that Razor was her older sister. Stryke turned on Von Drake and the two women defeated Von Drake but Nicole, not realizing who Stryke really was, left the younger woman for dead.
This angered Jacklyn who decided to kill Razor despite their family connection. Jacklyn eventually tracked her sister down and after a grueling fight killed her sister. Razor would be restored to life by her family descendant, Poizon. The three women were needed to stop a resurrected Von Drake. Only by mystically merging together were the trio able to finally destroy Roman Von Drake. A side effect of the merger meshed the three women's psyche's (Stryke became more passive after absorbing some of Nicole's child hood traumas, Nicole became more sexually assertive).
Stryke would eventually search out her associate and some time lover, Greco after she dealt with some more personal issues.
Jacklyn is a world class assassin versed in many fighting and killing techniques.