Gothorita is Mio's third Pokemon she owns during the festival. He debuted as a Gothita in Mio And The Gothita!, she caught him after Mio found it doing cosplays which embarrassed Mio.
In "What's In a Nickname?", he was officially nicknamed Gothman by Mio, and even nicknamed the other Pokemon she has. It evolved into Gothorita in Stepping to the Gothic Battle! after trying to protect Mio from Gourgeist's Dark Pulse. As a Gothorita, he is very sensitive like his trainer and is very frightened and a bit of a scaredy-cat which matches Mio. In a future episode, it is revealed that he will evolve into Gothitelle according to the intro.