Meloetta is a Mythical Pokémon first introduced in the fifth generation games Pokémon Black and White. In Villains War: The Age of Animation, she has a fairly small yet vital role in the war, serving as the reason as to why Mok caused the war in the first place, and how Amon finds access to the spirit of darkness Vaatu.
Villains War: The Age of Animation[]
The Resurrection[]
Meloetta is one of the few heroes that appears in VW:TAOA, taking the role of a reincarnation of Mok's daughter Melody, and first appearing being returned to life, happy to see her father again.
The Gateway[]
Through presumably some form of bloodbending, or perhaps just a threat, Amon has Melody sing a song of location, using the music to track down a mythological spirit he can merge with, finding out about Vaatu, the spirit of darkness, much to Mok and Holli's annoyance and mistrust.