- "Wait. What should I tell the police?"
"Tell them those Tae Bo tapes really paid off."
- ―Sylvia Prell and Phil Coulson
Sylvia Prell was working a night shift when Agent Phil Coulson of S.H.I.E.L.D. arrived to buy donuts and fill his car with gas. Two robbers entered and began threatening her with shotguns, ordering her to empty the cash register. Coulson distracted the robbers by throwing flour at them while he passed them his gun, and in the confusion he knocked them both unconscious. Coulson paid for the donuts and told the clerk to keep the change. She asked him what she should tell the police when they arrived, and he suggested that she take the credit by telling them that she knocked out the robbers with Tae Bo.
The next evening, Clint Barton arrived at the station. Seeing that it was a crime scene, he asked Sylvia if someone had robbed the station. She replied that someone had attempted to rob it the previous night. He asked if mysterious men in black suits had broken up the heist, and she was surprised by the accuracy of his guess.
During the start of the Inhuman Outbreak, Sylvia was known to be a descendent of Inhuman lineage and had went under Terrigenesis which allowed her to activate her powers. This gave her the ability to transform herself into an organism of pure electricity and had trouble controlling her powers. She became a target to the Watchdogs, but every time she continues to flee while using her powers.
Months after Hive's death, Sylvia was found by S.H.I.E.L.D., who was quite interested in powers and recruited her to join the government. Earning her own codename as "Fulmina", Sylvia joined the Secret Warriors, a team of recruited Inhumans that would serve as S.H.I.E.L.D.'s sect.