An ability that only Greninja from the Pokémon Sun/Moon demo have. In gen 7 when a Greninja with this ability knocks out a Pokémon it will become Ash-Greninja, this transformation also makes Water Shuriken stronger, raising it to 20 base power and making it guaranteed to hit 3 times. In gen 9 Greninja no longer becomes Ash-Greninja and it will instead raise Greninja's attack, special attack, and speed under the same conditions. Greninja with this ability are also always male, cannot breed, and shiny locked.
Girl: Hey what ability does your Greninja have?
Boy: My Greninja has the ability Battle Bond