Do filler episode characters ever appear in the main storyline? Do any of the characters from the Naruto filler arcs or movies show up again in the main series, or they are just strictly made for the fillers and movies?

I was watching Shippuden season 1 and at some point the opening and closing songs had scenes from the Priestess Shion movie, or the first Naruto Shippuden movie.
Utakata was introduced during the so-named Tsuchigumo Kinjutsu arc, but he eventually makes his way in the main storyline as a reanimated ninja fighting in the Great Shinobi War.

It could be conjectured that he wasn't a filler character, but until Naruto chapter 515 at the earliest, the Six-Tails host was not identified by name.



In this picture, Utakata is second from the left.