I like the idea that Batman is what gives Penguin the ability to rise.

While Riddler is the main antagonist for Batman, the Falcone family also falls and gives Penguin the ability to rise.

It would be great if the next film also left another hole for Penguin to fill and rise up in. Ideally something political in nature. Then Penguin can spend season 2 rising up the political ranks. Then the third Batman film can be Mayor Penguin.