In My Little Pony: The Movie (2017), Tempest Shadow
is never shown with a cutie mark. As an adult she is always wearing her suit of armor, and as a filly in a flashback she doesn't appear to (yet) have a cutie mark.
Does Tempest have a cutie mark?
One might imagine that it has something to do with
berries or soft drinks (as suggested by her "real" name)
but there's no proof that that is so. It seems plausible that she may never have had a cutie mark to begin with if she began her villain journey before gaining one. Other pony villains (Nightmare Moon/Luna, Sunset Shimmer, Starlight Glimmer) were seen in the show or a film with cutie marks.