You are the god of the three realms after being chosen as the next god of such realm where the three main beings Human kin, Angel kin, and Demon kin were always at odds with each other but they obeyed their previous god thus they don't dare to fight against each other to avoid angering the god.
You can choose to do much stuff as the successor and may promote the war between each other for your own entertainment as you can also do stuff with them.