Nerona Imu

Saint Nerona Imu was one of the twenty kings who founded the World Government after the Void Century 800 years ago. The person has been theorized by Emporio Ivankov to be the true identity of Imu, the secret occupant of the Empty Throne in the present day, them having achieved immortality through unknown means.

Abilities and Powers
As one of the twenty founders of the World Government, Imu ruled the world alongside the other royal family heads 800 years ago.

Egghead Arc
On Momoiro Island, after Sabo had finished explaining to Dragon and Ivankov what had occured during the latest Levely, Ivankov theorized that the mysterious Imu who seems to rule the World Government in secret is Nerona Imu, who could have been given eternal life by a previous user of the Ope Ope no Mi. Ivankov noted that he could imagine no one else but one of the First Twenty to hold the power to outright order around the Five Elders, who are publically the World Government's heads as the highest-ranking Celestial Dragon.

Trivia

 * The book Ivankov uses to identify the possible connection between Imu and Saint Imu is titled "Genesis", likely a reference to the Book of Genesis, the first book of the Christian Bible that details the creation of the universe by God.