Frontier Brains (Japanese: フロンティアブレーン Frontier Brain) are the owner of a facility on a Battle Frontier and are of the highest rank, much like a Gym Leader is to a Gym. Similar to a Gym Leader's Badge, Frontier Brains will hand out an item to a Trainer that proves their skill and is a sign that they have been beaten by that Trainer. Hoenn region Frontier Brains will give out Symbols, while Sinnoh region Frontier Brains will give out Prints.
In the anime, Ash managed to defeat the first five Frontier Brains on the first try while it took him two tries to defeat Salon Maiden Anabel and three tries to defeat Brandon, the lead Frontier Brain. After Ash finally defeated, Scott (revealing himself as the owner/founder/head of the Battle Frontier) offered Ash the chance to become a Frontier Brain himself. Though Ash considered the offer, he turned it down because he still wanted to pursue his dream of being the world's greatest Pokémon Master.
Hoenn Frontier Brains
|Salon Maiden |
Sinnoh & Johto Frontier Brains
|Hall Matron |
So far, the only Frontier Brains to appear in Pokémon Masters are both Factory Heads.