Suggested by Eric Kuvira and Toph are both very skilled at manipulating the ground and metal. Toph is heavily implied to be a supreme user of these forces in her prime, but we never got to see that. We got to see her as a kid and then as an old woman. Neither of these forms would be able to contend with Kuvira’s sheer speed. Until I see something a little more impressive from Toph, I just don’t think she has what it takes to win here. Kuvira wins.