I don't have evidence so it will just be speculation:
The comparison between Imu and Doflamingo has been made a lot of times by now. And we know we can predict the future with what we have seen in past arcs. What if Doffy and Imu were the same. Joyboy wanted to do so many good things. He was the one bringing all the kingdoms together and tried to make a world of working together. But the moment Joyboy was going to bring the Fishmen to the surface he got betrayed by his own child. Like Doffy betrayed his father. Imu wanted power and found it in devilfruits and the Gorosei. Joyboy had to fight former Gorosei Zunisha and won, but the others were to overwelming. Joyboy was the father, Lilly was the mother and Toki was the sister.
The comparison between Imu and Doflamingo has been made a lot of times by now. And we know we can predict the future with what we have seen in past arcs. What if Doffy and Imu were the same. Joyboy wanted to do so many good things. He was the one bringing all the kingdoms together and tried to make a world of working together. But the moment Joyboy was going to bring the Fishmen to the surface he got betrayed by his own child. Like Doffy betrayed his father. Imu wanted power and found it in devilfruits and the Gorosei. Joyboy had to fight former Gorosei Zunisha and won, but the others were to overwelming. Joyboy was the father, Lilly was the mother and Toki was the sister.