Are you going to make a sequel to earth and fire?
Maybe the comics era or the Lok.
Like in the Korra era there's a prequel which is a summary of toph and the OC's married life(and how having a father effects so and lin) and possibly the OC's death which leads to toph going to the swamp. Thinking he could die a few years after Korra is discovered as the avatar, it gives him time spend with the new OC. Lins son and Korra OR asami's love interest