Metahuman Purge (Earth-1: Pre-Crisis)

"Every Meta will die!"

- Cicada prepares to kill again

Cicada's Purge are a series of murder executed by Cicada I and II in 2018 to 2019 in order to kill all Metahumans in the city.

Orlin Dwyer
During the Enlightenment, the S.T.A.R. Labs Satellite fell from the sky to Central City. The Flash and XS destroyed the satellite before it hit the ground and saved thousands of people. However, Orlin Dwyer and his niece, Grace Gibbons along with hundreds of people were under the impact zone and was injured by shrapnels of the satellite. Orlin, who was impaled by a lightning bolt-shaped shrapnel was mutated in the process and gained Metahuman powers. Grace, on the other hand, was hit by a small piece in the head and fell into a coma.

Days later, Orlin was angered by Grace's coma and chose to seek revenge for her. The shrapnel placed next to him was activated and he discovered his power of power-dampening. He then used his mask at work, utilized a hooded jacket and chose to be a murderous vigilante, later known as Cicada.

Grace Gibbons
At some point before 2018, Grace's father and mother passing by an ATM and was killed by an explosion unknowingly caused by Vickie Bolen's powers. She was later sent under her uncle's guardianship and grew up taking up his mantle as Cicada in an erased future. Soon, Grace traveled back in time before her own uprising to stop Orlin from taking the Metahuman Cure and tried to do the purge on her own way.

Secret Plan
Unbeknownst to all, Eobard Thawne has been planting seeds to start the purge by sending Nora back to the past in order to free himself from the imprisonment by the Lightning Dagger in 2049. Despite his connection with Nora being discovered by Sherloque Wells, no one has been able to deduced that Cicada's Purge is connected to his plan. Moments before his plan succeeding, Ralph Dibny realized that it might be tied to Thawne and prevented the detriment of the dagger. However, Team Flash did not understand Ralph's motive of the action and destroyed the dagger again. After Ralph being reverted to his default form, he told them that it might related to Thawne's imprisonment and the team went to 2049 to prevent Thawne from escaping, leading up to a battle in 2049.

Trivia

 * The purge only takes place in Central City and Metahumans in other cities were not considered as targets of Cicada.