According to the spoilers for the upcoming One Piece manga chapter 1016, the fight between Nami and Ulti will continue and end. However, Nami will be assisted be her reunited ally in Zeus, who survived the attacks against him a few chapters ago. Zeus was expected to be deceased after the events from chapter 1014 of One Piece.
Together, Nami and Zeus will crush Ulti, ending the chapter. Sadly, there will then be a one-week break before we get One Piece manga chapter 1017. This means that One Piece manga chapter 1017 will be released on the 26th of June.