Delta Pokémon
From The Pokemon Insurgence Wiki
Delta Pokémon are a special kind of Pokémon whose type and appearance differs from their normal counterpart. Delta Pokemon were based on an idea scientists had about Pokémon to make them perfect.
In the game
Shortly after the events in Cult of Darkrai the player decides to start his Pokémon journey and seeks out Professor Sylvan to obtain a starter Pokémon. Upon entering Professor Sylvan's lab the player interrupts a conversation with Reukra and Professor Sylvan about Delta Pokémon. Reukra suggests that the player and Damian take the Delta Pokémon instead of releasing them into the wild.
There are other Delta Pokémon the player may encounter throughout their journey. It is not known if these Pokémon were genetically modified or a natural mutation.