The Rotom Pokédex (Japanese: ロトム図鑑Rotom illustrated encyclopedia) is a Pokémon that Moon owns in Pokémon Adventures and her fourth overall. It originally traveled with Moon to Alola before being given to Professor Kukui who put it in Moon's Pokédex.
Rotom and Moon
Prior to the start of the Sun, Moon, Ultra Sun & Ultra Moon chapter, Professor Kukui searched for a Rotom in order to have it inhabit one of his special Pokédexes. His request was eventually answered by Mr. Berlitz, who arranged to have it delivered to Kukui. Due to its own weakness, Rotom couldn't be delivered electronically, so Moon was given the task of hand-delivering it from Sinnoh to Alola, whose pharmaceutical skills kept it healthy along the way.
Rotom debuted in The Grand Entrance and Delivery Boy Sun alongside Moon. After encountering a delivery boy named Sun, Moon and Rotom were taken to meet Professor Kukui at his house on Route 1. Kukui attempted to have Rotom inhabit Sun's Pokédex, but due to Sun's poor handling of the device, Rotom ran away in disgust. Sun was then punished by Kukui and forced to spend the rest of the day retrieving Rotom.
In The Final Match and a Surprising Finale!, Rotom was revealed to have possessed a second Pokédex Kukui had given to Moon. After returning Sun's Pokédex, Rotom revealed it had chosen to stay with Moon.
In A Photoshoot and the Abandoned Thrifty Megamart, Rotom appeared to help Sun during his trial at the abandoned Thrifty Megamart, revealing Sun was holding onto it when he fought Bruxish. With its Poké Finder function, Rotom served as a replacement for the camera Sun was using to take a photo of the TotemMimikyu he was fighting. After befriending Mimikyu and convincing it to join his team, Rotom took a photo of them both, successfully completing the trial. Afterward, Sun thanked Rotom for his help and suggested it join his team, which Rotom rejected, preferring to stay with Moon.
By the time Moon arrived in Ultra Space, Rotom had rejoined her, using its abilities to keep track of the time Moon and Sun spent in the Ultra Deep Sea. Later, it managed to sense the arrival of Lunala, who would be able to take Moon and Sun back to Alola. Upon meeting with Lunala, they discovered the Ultra Recon Squad members Zossie and Dulse riding it.
After Moon returned to Alola, she was separated from Rotom once again. Later, Rotom appeared before Sun during the battle between Zygarde, and Ultra Necrozma, informing him about Zygarde's weakness. Despite this, Zygarde still ended up defeated. After Necrozma was defeated, Rotom returned to Moon.
Personality and characteristics
Rotom displaying Pokémon information
Rotom is very weak compared to normal Rotom and cannot handle being electronically transferred. It was shown to have an interest in the Pokédex even before possessing one. Rotom has a great fondness for Moon as it was shown to be very angry when she was attacked by a Team Skull Grunt and choose to possess her Pokédex over Sun's. It also enjoys traveling with her and likes that she acts on logic and reasoning. Rotom has a strained relationship with Sun and often berates him and is shown irritated with him, once turning down Sun's offer to join his team as it preferred to stay Moon's Pokémon. After Rotom inhabited the Pokédex it often gives others helpful advice about the Pokémon around them. As a Pokédex Rotom has the ability to scan Pokémon and give information on them, translate speech between humans and Pokémon, act as a camera, send emails, and find previously seen Pokémon.