Pokémon Legends: Z-A is ushering in its next seasonal update for online battles, introducing a significant shift with Season 16. Beginning on August 27 and running until September 17, this new ruleset will exclusively allow Pokémon that have the ability to Mega Evolve. Furthermore, Mega Stones will be the only type of held item permitted for use in Ranked Battles during this period.

Mega Evolution, the central combat mechanic of Pokémon Legends: Z-A, allows certain Pokémon to temporarily transform during battles. This transformation not only alters their appearance but also provides a substantial boost to their stats. To trigger a Mega Evolution, a Pokémon must hold its species-specific Mega Stone. While only the final Pokémon in an evolutionary line can achieve this form, not every fully evolved Pokémon currently possesses a Mega Stone.

The game has reintroduced several Mega Evolution forms from previous entries in the franchise and introduced new ones. The new ruleset, while limiting the roster of available Pokémon to a few dozen, still includes popular choices such as Charizard, Gengar, and Lucario. Pokémon introduced in the Mega Dimension DLC, like Tatsugiri, will also be eligible for battle. A guide detailing Mega Evolutions, Mega Stones, and eligible Pokémon for Season 16 is available for those seeking more information on how to acquire these items.

Ranked Battles in Pokémon Legends: Z-A feature a four-trainer, real-time combat system. Each trainer will field a team of three Pokémon, and points are awarded for each opponent's Pokémon that is knocked out. Regardless of their current level, all Pokémon participating in Ranked Battles will be set to level 50.

Similar to the previous season, players who rank up through the tiers from Rank Y to Rank S will receive specific Mega Stones as rewards. These include Greninjite, Delphoxite, Chesnaughtite, Baxcalibrite, Sceptilite, Swampertite, and Blazikenite, awarded sequentially for each rank achieved. A complete list of these rewards can be found on Serebii.