What is the answered supplication for taking revenge on the oppressor?

The wronged person should be patient and forgive whoever wronged him, as Allah Almighty says: "So pardon and overlook" and "But whoever is patient and forgives, indeed that is of the matters [requiring] determination." And he should ask Allah to guide his oppressor or to avert his oppression from him. He may supplicate against him to the extent of the injustice, without exceeding it. It is permissible to supplicate for death upon a disbeliever and an oppressor.