3) Echo
It’s no wonder that Daredevil’s pissed at the Kingpin, as the crime mogul seems to take particular delight in attacking Murdock through the women he loves. Just take Echo for example.
After the Kingpin killed her criminal father, he adopted the young Echo and raised her as his own, convincing the now trained assassin that Daredevil was the one really responsible for her fathers death. Using the ability to perfectly copy the movements of others, Echo became an Olympic-level athlete who could replicate and match Daredevil’s martial art skills with ease, eventually besting him in battle. Just before Echo could deal the killing blow to Murdock, the man that she had grown to love, Daredevil revealed his secret identity. Upon realizing that she had been manipulated by the Kingpin, Echo sought revenge by shooting him in the face.
Not one to do things by halves is our Echo.
Once the TV series is more established, Echo’s introduction could kickstart a chain of events that would eventually lead to the Kingpin’s downfall, mirroring the comics in an epic fashion that could become the basis of an entire season arc. It also wouldn’t hurt to have a deaf Native American character appear in a cinematic universe that still rarely represents minorities of any kind.