Based solely on the provided details, the optimized character description for Iona Hikawa/Cure Fortune in *Eiga Precure All Stars: Haru no Carnival* is:

Iona Hikawa appears as Cure Fortune in *Eiga Precure All Stars: Haru no Carnival*, joining 39 other Pretty Cure warriors within the ensemble cast during the Harmonia carnival events. Her individual role, background, character development, and specific actions during the film remain unexplored. The trailer features an animation inconsistency where Cure Fortune is shown with a LovePreBrace, which she does not possess in her main series.