Square Enix has decided to take a look at the PvP reward system within Final Fantasy XIV. As such, the Series Malmstone system has been introduced.
The Series Malmstone system provides unique rewards to players who participate in PvP during a given "Series." A Series is a period of time that lasts the duration of one major patch (6.1 until the release of 6.2, for example). Players will be able to level up to the cap of 30 during a Series. Increasing this Series level will unlock various Series rewards. Additional levels past 30 can be gained as "extra levels."
The use of seasonal or "Series" content is nothing new to many games. It has proven extremely popular, especially in the FPS genre with titles like Destiny 2, Call of Duty, Halo Infinite, and Fortnite. It's a way to entice lapsed players to come back and to give current players something else to do. It also creates a fear of missing out as the rewards are typically exclusive to a particular season.
For more Final Fantasy goodies, check out How to obtain the GARO Collaboration items in Final Fantasy XIV on Pro Game Guides.