In Chapter 1086 Oda gave us hints about the Meaning of Imu’s Real Name

Imu is the one who occupies the Empty Throne. The full scope of Imu’s abilities and power is unknown, but the fact that they sit upon the Empty Throne, a seat whose occupant would be associated with sole authority over the entire world, plus the fact that the Five Elders—who are publicly considered the World Government’s highest authorities—bow down before Imu and address them with a great honorific, indicates that Imu indeed holds the highest authority within the World Government. However, Imu’s existence is kept an absolute secret within the government and the world at large, to maintain the lie that there is no singular ruler of the world.

Emporio Ivankov has hypothesized that Imu may be one of the First Twenty from 800 years ago, a member of the Nerona Family named Saint Nerona Imu, who would have received the “Perennial Youth Operation”. This belief is strengthened by Marcus Mars referring to Imu as a “Creator” in the same way as the First Twenty are referred to, although whether this is true is unknown as of now.

An interesting point that I realized about Imu’s full name reveal is that the name, Nerona Imu, when written in katakana, can be combined to form the kanjis meaning “God” and “Buddha”.

Nerona = ネロナ = 神 (“kami”) = God

Imu = イム = 仏 (“hotoke”) = Buddha

When you combine the two kanji characters, 神 and 仏, you get 神仏(“Shinbutsu”), which is a word that is generally used to refer to the collective notion of all deities.

That’s all. Just food for thought.