Played by Danny Trejo, Breacher will force Cisco to "prove his worthiness" after finding out about Cisco's relationship with his daughter Gypsy (Jessica Camacho) in The Flash season 4.
In The Flash season 3, Cisco developed an attraction to Gypsy, a dimension-hopping bounty hunter from Earth-19 who tried to capture H.R. Wells. For the life of H.R., Cisco challenged her to a trial by combat and won. After repeatedly refusing his advances and denying an interest in long-distance relationships, Gypsy finally relented and began a relationship with Cisco. The two worked together to fight the invasion of the gorillas from Earth-2, and teamed up again to defeat Kadabra, a villain who murdered Gypsy's partner many years ago.
In an interview with Collider, Jessica Camacho talked about her character's relationship with Cisco, and being "ridiculously stoked" when she found out that Danny Trejo would be playing Gypsy's father, Breacher. Camacho says that Trejo "will not let the audience down." Talking to CBR, Camacho revealed that Cisco will have to "prove his worthiness" to Breacher:
Her dad is quite terrifying. He is quite protective of his baby girl. In his eyes, no man is going to be good enough for his little baby girl. Enter Cisco, who abruptly meets him. Cisco is forced to prove his worthiness to Breacher. Just as bad ass as Gypsy is, the apple doesn’t fall far from the tree. We see the source of her intensity. We see that in Breacher. He’s ready, upon meeting Cisco, to see what he’s made of.
Breacher has been described by showrunner Andrew Kreisberg as part of the "slight redirection of the series" to tell more fun stories. Fans are looking forward to what will hopefully be hilarious interactions between Breacher and Cisco. Breacher is likely to be enraged when he discovers that his daughter, a "strong, fierce, independent woman" has become a "ball of mush for her honey," according to Collider.
Trejo's Breacher will appear in the fourth episode of the season, titled "Elongated Journey into Night", which will also feature the debut of Elongated Man/Ralph Dibney (played by Hartley Sawyer). According to the episode's synopsis, Breacher will take an immediate disliking toward Cisco and will decide to hunt him down.
The Flash continues tonight with ‘Mixed Signals’ on The CW.