14 (Platinum Arc)
Caitlin debuts in Chapter 418.
She hears Looker call "Lady" and mistakenly thinks he's speaking to her. Looker apologizes for the misunderstanding, reaching out to pat her shoulder, and Caitlin's Gallade, considering him a threat, strips Looker down to his underwear. Caitlin then walks with Gallade into the Battle Castle, where she watches Platinum and the other challengers battle.
For the sixth battle of Platinum's second set, Caitlin awards her 26 CP.
Caitlin watches Platinum fight Darach. Afterwards, she explains Platinum's strategy to Looker.
Caitlin first appears at the Pokémon League in discussion with the other Elite Four members. She says that she isn't bothered by Alder's defeat and subsequent abandonment of the League—that was inevitable—but she is worried about the effect it has had on the people of Unova, as the audience for the Pokémon League tournament is unusually small.
When Marshal suggests that they stop Team Plasma, whose speeches have taken effect, Caitlin points out that Team Plasma has the right to hold their own opinions. However, she is not willing to stand by and allow the kidnapping of the gym leaders. With the help of her Gothitelle, Caitlin psychically searches for the gym leaders and is able to determine that they are still somewhere in Unova. She is also able to convey a message from them: "Help."
In the Platinum Arc Caitlin could not battle, because she would become a different person.
- Psycho Cutter
Gothitelle helped Caitlin communicate with the kidnapped gym leaders.