The Rank X update is hitting Splatoon 2 tonight, and we've got the details on what's in store. Splatoon 2 3.0 brings with it tons of new guns, a new ranked mode, 100 pieces of new gear to collect (some new, some returning from Splatoon 1), and the storied return of Callie... no spoilers, just that she's coming back after players meet a "certain requirement" according to Nintendo.
From the release:
X Rank is an extremely challenging Ranked Battle experience targeting the best-of-the-best players. Players who are S+10 in the current Splatoon 2 ranking system will automatically be registered as X Rank after downloading the update. Players who are X Rank will battle for an X Power level. Once a month, 500 players with the highest X Power level for each of the four different Ranked Battle modes will be announced within SplatNet 2, a service of the Nintendo Switch Online app for mobile devices.