While escorting Kuvira to confinement in Zaofu, Asami, Bolin, and Mako were ambushed by Guan’s men and taken to a “re-education camp” were Guan had Doctor Sheng brainwashed them into serving the Earth Empire and seeing Korra as an enemy

During a battle against Korra and their other friends and allies, Asami was able to be captured by Korra and was taken to Suyin’s estate. There, they manage to restrain her to the device that brainwashed her in the first place in order to reverse it. But the more they tried, the more it wasn't working

Asami: still strapped to a chair and hooked up to the machine I am only loyal to Commander Guan. I only live to serve the Earth Empire. Avatar Korra is my enemy and must be eliminated.