Her build up was very organic. I was legit shocked when I started season 4 and realized who she was and saw she was going to be the big bad. Saw her fight alongside Su and everyone else, and she held her own in a number of spots in season 3. Its kinda really fukking dope how they didnt just throw someone new in there but had someone they were building for the moment who saw the opportunity to seize the moment and did so.I like her more than Zaheer. They didn't even give him a backstory or put focus on WHY he is who he is.
And she's just a badddddd bytch. LAWD i love me some Kuvira.
I'm okay with the lack of explanation on Zaheer, though. I think they gave enough of a backstory. I don't need to know how he was raised and everything.