In essence, each arc has a series of volume covers. Oda has a pattern. Chapter 1006 has the cover what showcases the villains, corresponding with Volume 100 which will presumably be a special cover. The volume with "The Villains" is the one where they start to fall. It's followed by "The Heroes" where the rest of the Villains fall. Followed by a "Clash" cover showing off "Luffy Vs the main antagonist".
It's a pattern in Enies Lobby, Dressrosa, Alabasya, Whole Cake, and even to some extent Marine ford. There's a cover that shows off "allies", I initially thought it would be Volume 98, but given the content of volume 99 and the cover of 1006, it's likely that 99 will show off the Straw Hats allies.
The key point was that PageOne and Ulti would be defeated at the end of Volume 99, later 100. PageOne is down. Nami Vs Ulti is continuing on from there.