Blaze is a primary ability restricted only to starter fire Pokémon. It's a pretty simple ability, when a Pokémon with Blaze uses a Fire-type move, the move's power will be increased by 50% if the user has less than or equal to ⅓ of its maximum HP remaining!
In Polished Crystal, starter fire Pokémon have additional abilities as well so you are not guaranteed to get Blaze when you receive one.
Game:Polished Crystal
