The Masked Man had Gastly take control of a child and his Farfetch'd, who were to stop any person. Gold faced Gastly and the other Pokémon the Masked Man sent. Since Gold refused to retreat, the Masked Man's Houndour used Iron Tail and his Gastly fired Shadow Ball to wound Gold and his Pokémon.
While facing the Masked Man, Silver remembered how the Masked Man used Pokémon, including Gastly, to serve his selfish desires.
The Masked Man sent Gastly, whose Curse affected Suicune. This made the latter distracted and unable to lower the crystal wall, behind where Misty was located. Fortunately, Eusine rescued Misty and had Haunter battle Gastly. Soon enough, Haunter defeated Gastly.