The Legend of Korra's third major villain was the anarchist Zaheer, and he's more like Korra than most would dare to admit.
Appearing early in season 3, Zaheer broke free from a White Lotus prison and swore to restore balance and harmony to the world his own way, and soon freed his compatriots from their own prisons. Together, they conspired to kidnap and murder the Avatar, which they believed was an important step for freeing the world of tyranny and rules. But Zaheer no thug -- he's a man with deep philosophical motives, and they connect him to Avatar Korra in surprising ways. In some regards, he's just like her.
His Mission
When Korra was very young, Zaheer joined the secretive Red Lotus organization and learned about Avatar Wan's historic separation of Raava and Vaatu. He was certain that the world was thus out of balance, and he and Unalaq conspired to have Korra trained to release Vaatu. But Unalaq pulled out of the plan, and Zaheer and his fellows ended up captured and imprisoned.
Once Korra restored humanity's connection to the spirits, Zaheer gained airbending and used it to free himself and his three fellows. They were among the last members of the Red Lotus, and they swore to take down all kings, queens and national boundaries. From then on, Zaheer promoted anarchy and populism wherever he went, and nearly killed Korra by poisoning her with mercury. Only with the aid of Jinora and the other airbenders was he stopped and was imprisoned once again. Three years later, he was still captive, but was willing to help guide Korra through the spirit world to aid in her quest to stop Kuvira. At this point, Zaheer no longer has any interest in breaking free or sowing anarchy in the world. His role is now that of a lofty, monk-like figure in Korra's life story.
His Idea Of Balance
Unalaq had tried to become a "dark Avatar" when he melded with Vaatu but, in principle, it's really Zaheer who became the dark Avatar. He saw the people of the world as one and the same and, like Huu and guru Pathik from The Last Airbender said, all things are really one and the same. Division is an illusion, and Zaheer agrees.
The main difference is that Zaheer used anarchy to promote that sort of unity, rather than peaceful methods. He and his comrades were willing to use force -- from genocide and assassination to freeing prisoners -- to achieve that goal. Zaheer wanted to give the world back to the people, by means of forcefully dissolving the city walls and national boundaries that the kings and queens had erected. Korra, as the Avatar, is also sworn to protect all people around the world, and isn't loyal to just one nation or leader. Korra loves her native Water Tribe, but her responsibilities go beyond her home. Where her duty is concerned, there are no borders.
Zaheer's philosophy is like a brutal variation of Buddhism, in that division is an illusion and that material gain is pointless. He sought the power of flight like the ancient guru Laghima, which requires severing all earthly tethers and ascending into the divine. Zaheer certainly does that, and even before then, he was skilled at meditating and entering the Spirit World at will. Never is Zaheer fixated on wealth or power; he sees such things as foul temptation or just illusions. Humanity must be free, from the pursuit of wealth and from the so-called tyranny of royalty and nations.
Zaheer, like Korra, aims to help all people regardless of their borders or origins and ascend to a divine state. He's just more brutal about it.