I rmb the episode when zhr blame her for xt gg blind, she was very very bitter about his misunderstanding.
Also when her dad went to see her for the last time and beg with her, she spitefully reply her dad that since he did not care when she point a gun to her own head to beg him, she will not care when he beg her now.
So my guess is the nice part and leaving organization was real emotions, but she was hateful to zhr for maligning her on xt case despite her trying so hard. So the initial revenge began.
Then when her dad came and commit suicide because she was grudgeful towards far because of zhr, her guilt drove her hatred for zhr further and her revenge evolve to a more vicious version?
Plus she must be under huge pressure from "uncles" and taking over with zero handover.
Ah I don't understand this too. She seemed like wanna help Haoren and become a good person, even snubbing her dad. Then suddenly become so evil, deal drugs and ask the Xintong to give Haoren crystal meth?