Eagle Flag of Epirus

Novel Summary
After 1204, the Byzantine Empire had fallen apart, but as the only successors, Nicaea, Epirus and Trabizon were still fighting each other, completely forgetting the hatred of the country and the family.
The Latin tyrant in Constantinople claimed to be the emperor of the Romans, while the Bolgar in the north was raging greed and devouring the legacy of the empire, and the Turks were also ready to eat their flesh and blood, but in the farther east. The potential power Mongols have also quietly emerged.
The collapse of the empire seems to have been completely irreversible, but how will Justinian reverse the already depressed situation and let the eagle flag of revival fly again?
– Description from MTL