1) Moon Knight
Despite some similarities to Batman, Moon Knight is a character that’s never even been rumoured to be in line for a movie or TV show of his own. However, with a mythology which stretches back to ancient Egypt and a split personality disorder which makes him one of the most psychologically complex comic book characters out there, Marc Spector being brought into the fold is something which needs to happen sooner rather than later.
In terms of an introduction, season 3 of Daredevil might work, though I’d argue that bringing Marc into the world of Jessica Jones would be more interesting at first, especially as that series could do with a costumed hero to appease fans disappointed that the first season didn’t really follow the Man Without Fear’s in that respect.