Responses
No clue honestly haha but he did say he was gonna return in ch300: http://www.mangago.zone/read-manga/one_piece/mr/one-piece/300/11/
No that's him foreshadowing that Nami will get Zeus back again
Remember Nami saying they would need a bigger lightning to defeat Ulti? Considering the foreshadowing skills of Oda-sensei, I think it is Enel