I would like to propose a unique npc with the aim of being able to change the form to the legendary event pokemon, I understand there are people who like the event form and those who like the original form, with volcanion for now you can not get the original form and I hope you can change its shape

Legendaries caught during the event get their special form and can be changed to normal afterwards, if you didn't catch it during the event you don't get it's special form. For the volcanion I think they'll add it in the future, so that you can change its form