(Leaf Blade isn't a signature moves since two pokemon family can learn it be leveling up as well as other pokemon can learn it by leveling up and Victini has two signature move)
A Signature Move is any move that is learned by only one or a few Pokémon, making it unique. Examples of signature moves are Volt Tackle, which is only learned by Pichu, and Chatter which is only learned by Chatot. Every signature move can be learned by at least 12 Pokémon: The Pokémon it is known by, Ditto when using Transform, Mew using Transform or Metronome, Smeargle by using Sketch, some by Mimic, and the rest by using Metronome.
