If a member of the Porygon family uses Conversion when Aerial Ace is in its first move slot, it will become pure Flying.
The Porygon family can use Conversion 2 and get lucky, scoring the Flying type, thus becoming pure Flying.
Kecleon can be pure Flying via its Ability Color Change. If it is hit with a Flying move, it will become Flying type.
Arceus can be pure Flying if you make it hold a Sky Plate.
Tornadus and Tornadus-Therian are pure Flying types.
Protean Greninja can become pure Flying if it uses Aerial Ace.
A Pokemon using Camouflage when soaring or in the Sky Pillar will become pure Flying.
Silvally can be pure Flying if you give it a Flying Memory.
Libero Cinderace can use Bounce, thus becoming a Flying type.
Rookidee and Corvisquire are pure Flying.
If Reflect Type is used against a pure Flying type, the Pokemon that used Reflect Type will also become pure Flying. This is easiest to achieve against Rookidee or Corvisquire.
