Cicada's secret may soon be revealed in the coming episodes of The Flash. What Team Flash doesn't yet know about the main villain of The Flash season 5 is that someone is pulling his strings, but this could change as early as next week's episode.
Though Team Flash has been able to defeat Cicada on more than one occasion, Cicada has managed to evade capture throughout the entire season. Flash's inability to apprehend Cicada has forced Barry Allen and his team members to come up with drastic solutions, like waking Cicada's niece from her coma, and their most recent plan: give Cicada the metahuman cure. Throughout their encounters with Cicada, none of them have come face to face with the person who's responsible for Cicada's actions. It turns out, Cicada is being manipulated by Dr. Ambres.
In The Flash season 5 episode 15, "King Shark vs. Gorilla Grodd", Jesse L. Martin returns from a medical leave of absence as Joe West. After Iris gets Joe caught up on everything that's happened, Joe notes that someone must be helping Cicada. This was an observation that Iris had no answer for. Joe's remark is a sign that at least someone close to Barry may take a closer look at Cicada. With Sherloque preoccupied by his investigation into Nora's secrets, Joe may be the one who finds out the truth about Cicada.
It was revealed early in The Flash season 5 that the person caring for Cicada's niece at the hospital, Dr. Ambres, has been protecting his secret. In a later episode, she even stopped Barry from finding him. She has also admitted to sharing Cicada's hatred for metahumans. In fact, it was Dr. Ambres who put it in Cicada's head that metahumans were responsible for Grace's condition. Dr. Ambres has since gone even further than protecting Cicada from Team Flash and the authorities. She was shown to have a more active role in the killings when she gave Cicada the CCPD's list of metahumans. That list sent Cicada on another killing spree.
As long as Cicada is listening to Dr. Ambres, he'll continue to be a threat to Central City. Team Flash's next mission could potentially put the two at odds, depending on how Cicada responds to Barry's offer to give him the metahuman cure. If Team Flash is able to reason with him, Cicada will certainly face fierce opposition from Dr. Ambres, who will try to stop him from giving up his crusade against the city's metahumans. It's possible that when Barry next confronts Cicada, the true mastermind will finally be unmasked.