Over the course of The Legend of Korra, each season's main villain represented not only a different threat but a different philosophy for Korra to confront. The final season's villain, the Metalbender Kuvira, who headed the rise of the totalitarian Earth Empire, was an engaging character and perfect threat to face off with Korra toe-to-toe. In the comic book continuation, Ruins of the Empire by writer Michael DiMartino and artist Michelle Wong, Kuvira even begins a path toward redemption as she atones for her crimes and salvages a better future. The only problem is that she does not deserve it. If any Korra villain does, it's Zaheer.
Although Kuvira was introduced in Book 3 as an ally -- the helpful captain of the Zaofu city guard, the time skip over the course of three years between that season and the next radically changed her. During that time the Earth Kingdom nearly collapsed into chaos as its assassinated Earth Queen left the people without a leader and bandits ravaged the land while it lay in disarray. When Suyin Beifong refused to step forward and take leadership of the flailing country, her protege, the talented Kuvira, stepped forward to fill the power vacuum. Suyin feared that the position would thrust too much power into any one individual's hands, and her fears were realized by Kuvira as the autocrat refused to give up her position of influence and instead became the dictator of a new Earth Empire.
Kuvira bullied the disparate provinces of the territory into joining her, holding valuable resources they needed hostage as an incentive while also marching her powerful military across the country as a show of power. Her regime set up "reeducation camps" where dissidents, Firebenders and Waterbenders were imprisoned and tortured. She even oversaw and accelerated the production of a doomsday superweapon that escalated humankind's destructive output to previously impossible levels. None of this sounds like the makings for the kind of villain that gets redeemed, and yet the comic sets out to do just that.
Ruins of the Empire at first has Kuvira stand trial, unapologetic for what she did. While she was unaware of some of the tragedies her Empire inflicted, she nevertheless presented a utilitarian argument for why her actions were justifiable for the greater good of her people. Delving into her backstory provided more psychological motivations, expanding on her tearful utterance in the series' finale about her parents abandoning her and revealing that Kuvira wanted to become a strong parent-like presence to a country she felt was abandoned.
During the course of the story Kuvira confronts a former underling of hers who attempts to reclaim the Earth Empire for himself, and in so doing, she cooperates with the rest of Team Avatar and hears the pained admonishments of the Beifong family along with them. She changes, in too short of a time frankly, into a haunted and apologetic figure. At the comic's end, she apologizes wholeheartedly for her actions and is confined to house arrest with the Beifongs where she begins to make amends... and she does not deserve any of it.
Kuvira's actions wrought devastating travesties on a global scale. She threatened entire cities, including at one point outright attempting to even kill the man to whom she was betrothed. If redemption was ever going to be possible for her it would necessitate years of recompense and meditation to even approach being justifiable. In fact, one of the few Korra villains to survive and show regret for his actions actually did have years to meditate on his mistakes -- and yet the series only briefly addressed him.
Following his assassination of the Earth Queen and attempt to end the Avatar Cycle, Zaheer was imprisoned as the last member of the Red Lotus for the three years in which Kuvira came to power. When Korra visited to confront him, the anarchist Airbender showed pain that his actions empowered a tyrant so contrary to his ideals, and his way of making up for it was to guide Korra through the spiritual healing necessary to move on as an individual. It was a touching and worthwhile way to redeem one of the best villains in the franchise adored by most of the fandom... and the series has yet to follow up on him.
Zaheer's closest friends and loved ones are all dead while he is chained to a prison cell even after rediscovering the gift of flight that remained a secret to humanity for generations. While his violent methods could never be justifiable, his philosophy always had some legitimacy in pointing blame at the monarchs of the Avatar world, and the centuries of violence and genocides they inflicted. Whereas Kuvira seemed more selfishly motivated by her own psychology and desire for power Zaheer's beliefs were grounded in a thought-out system that is, at least, somewhat justifiable.
If the comics are to continue their pattern of redeeming surviving villains then Zaheer would be the best target to focus on. Whereas Kuvira's redemption comes across as confusing and ethically muddled, the master of the void deserves all the screen time creators are willing to give him. Unshackled, there's no telling where Zaheer's story could fly.