During the time she was kidnapped, Green was taught to develop her knowledge on Pokémon evolution, having won important battles with the appropriate use of evolutionary stones. Due to her skill, she is defined as the Evolver. The first time Green went in Professor Oak's Laboratory was when she stole his Squirtle. After being defeated later, the trainer's true identity was revealed to be Professor Oak himself, who already knew of her coming from the beginning and had let her steal his Pokémon since it was already intended to be hers. Then, he handed her her own Pokédex.