Which character achieves the ability to fly in Book 3?

Zaheer achieves the ability to fly in Book 3 of The Legend of Korra. He unlocks this extraordinary power after the death of P'Li, the person he loves most, by letting go of his final earthly attachment.

Zaheer was already a dangerous martial artist and anarchist leader before Harmonic Convergence unexpectedly gave him airbending. He quickly studied airbending principles and became an unusually skilled combatant, despite lacking the lifelong training of traditional Air Nomads.

His flight follows the teachings attributed to Guru Laghima, an ancient airbender who wrote about freedom from earthly attachments. Laghima is not the character who newly gains the ability in Book 3; he is the historical figure whose philosophy inspires Zaheer. Jinora, Tenzin, and the other airbenders can glide and maneuver through the air, but Zaheer is the one who achieves true unaided flight during the season's climax.