OK, so this will sound crazy and you might think im trolling but im not. So nobody get mad because this speculation is literally a long shot but im a believer that Enel/Eneru is still relevant to the One Piece series. Why? Because he has a logia DF ability thats just too powerful to ignore. Its only fair that he was defeated by a rubber man. Enel/Eneru also possessed observation haki (Mantra) & most likely hasnt had his DF for very long (At Skypea) & could also be referred to as 'a rookie' of some sort. Hes a man who basically chooses to live in the sky lands and who else could possibly live in the sky? Shiki. I also believe that shiki will be making his appearance very soon. With saying that I have a feeling that Eneru ran into Shiki at some point on a Sky land (Most like Shikis Sky ship) & was defeated by Shikis haki. Shiki seen potential in him and taught him how to perfect his Mantra & Haki thus becoming Enerus master. Having taught Eneru he should be very strong now and could possibly rival the observation haki of Katakuri. Maybe even better. I have NO EVIDENCE of this theory but these are my honest thoughts and I really think you readers should remember this. Thanks for reading and I hope you enjoyed my crazy imagination P.S Im open to all your thoughts and ideas on this. Have a good day.