Battle Frontier (Generation ζ)

The Battle Frontier (Japanese: バトルフロンティア Battle Frontier) is the main form of Pokémon battling within the Aero region, and is accessible once players of Pokémon Aether, Nether, and Tether Versions manage to defeat Volundr and acquire the Skill Badge, unlike previous incarnations in which the Battle Frontier can be only accessed after the player has completed the Pokémon League. Like the previous versions, however, it consists a variety of arenas in which Pokémon Trainers of great strength can battle each other. Similar to the anime, the Battle Frontier is spread out throughout the region, or rather, the Battle Frontier makes up the majority of Aero, with most residents living around the various facilities, and most automated transport connecting the various arenas rather than major towns or similar establishments (the main exception to this happens to be the variety of airports in the region, which sport their own transportation systems independent from those of the Battle Frontier). The way to arrive in the Battle Frontier is identical to the way one arrives in Aero itself: one can either travel there directly from other regions, arriving by way of one of the various aiports, or travel through the notoriously hard-to-navigate Strait of Tears, which will deposite one directly in front of the first arena. From either of these points, a Trainer can begin their journey through both the region and the frontier.

Like its counterparts in other regions, a challenger must fight their way through a variety of other Trainers in each facility, until they acheive one of several winning streaks available in each area. Once this has been done, they may face off against a Frontier Brain, and if they manage to successfully defeat them, they can acquire either a Silver or Gold Emblem to symbolize their victory. Much like other Battle Frontiers, each arena features its own set of rules and methods in which it can be conquered. The Frontier Brains themselves are by far some of the most influential people in the entirety of the Aera region, and due to this, they often find themselves dividing into factions in order to decide the fate of the region itself, causing tense rivalries to form between the them. The player is free to 'ally' themselves with one of the two/three possible sides in this sub-conflict, or choose to remain neutral and simply continue to play, though some story events are missed if this method is chosen.

The Battle Frontier plays a major role within the Pokémon ANT fanfiction series as well.