• English / United States: Weston's Rotom
• Japanese / Japan: ヨルトンのロトム
• Japanese (Romanized) / Japan: Yolton no Rotom
• Japanese (TL) / Japan: Yolton's Rotom

Weston's Rotom lives at a fine hotel located near Hyakokku City in the Kalos region with its owner Weston. It originally lost a battle against Mantle's Krookodile because it was afraid and lost the battle. As a result of that loss, Weston had to transfer ownership of the hotel to Mantle. In the 10 years since that battle, Weston's Rotom had time to think of what happened that day.

Ash Ketchum and his friends travel back in time 10 years with the help of Weston's Rotom. It has some kind of special power that allows it to time travel and also allow others to time travel with it.

The strategy in the rematch battle in the past was a Forme changing strategy in order for Weston's Rotom to overcome its normal weakness against Mantle's Krookodile. It proved to be a super effective strategy and Weston's Rotom was able to defeat Mantle's Krookodile so that Weston could retain ownership of the hotel.

In the present, Rotom spotted Ash Ketchum and his friends at the gathering for the tenth anniversary deluxe party for the hotel. It then showed them a picture that was taken 10 years earlier at the opening of the hotel to confirm to them that they had indeed traveled in time and it wasn't just a dream.