Arrow: 7 Plot Threads The Show Totally Abandoned
2. Huntress
Oliver Queen's fleeting and turbulent romance with Helena Bertinelli in the first season had fans quickly falling head-over-heels with the woman who would be Huntress. Her bad attitude and reckless behaviour made her a perfect fit for the show, while Jessica De Gouw looked amazing in the outfit.
Her character journey was defined by her desperation to destroy her father - who wrongly murdered her fiancee when he thought he was spying on him for the FBI. Though that led to multiple fun adventures, including a great showdown with The Canary, her father ended up dying as the result of the SWAT team's gunfire.
In spite of fans' pleas for Helena to return, she never reappeared on-screen after her imprisonment (though she did appear in the Season 2.5 comic). Season 7, however, suggested that she suffered a grim fate at the hands of a vigilante hunter - who possessed her mask.
As the character is referenced multiple times in the backdoor pilot for spin-off show Green Arrow and The Canaries, we can assume that her destiny was rewritten post-Crisis - even if she does go missing again.