A Theory on Kuvira's Plan [Spoilerish?]

[CreativeButLazy]

ShizunaxShiawase

I think Kuvira is going to go all firelord ozai and totally lose her marbles somewhere along the line, and become a sort of stalin dictator of the earth kingdom ready to eradicate anyone who is willing to step up to the mark, using coercion and black mail to do so.

Another theory is that Kuvira is Lenin and will have something happen to her be succeeded by a Stalin.

[nitznitz]

I think she's gonna try to unite the United Republic into her Earth Empire, which means they call in the Fire Nation.

[Lewyn]

It's clearly going off of The End of Imperialism of the 1930s. Where China was torn apart with War, Rebellions, and different Political Ties.

Most likely it's going to end with a Spirit Bomb similar of that as a Nuke. Which will probably be aimed at Republic City. To show the other Nations their power. I bet either Korra jumps in and sacrifices her own life to save everyone. Or that Zhu Li sabotages the launch, trying to save as many people she can something Veric wouldn't do. Could be why they were hinting at a relationship forming between them.