I'm always hyped for limited banners/events so looking forward to this one! I think people are speculating that it will be a fire facility event, but who knows!
I think the 5* unit might be a staff? We haven't had a new 5* staff unit but I think every other weapon has had a new 5*. But then the 5* for these seasonal banners are usually the main story characters (except for New Years which is like a zodiac thing) and I don't really see Euden, Luca, or Ranzal holding a staff...I'm thinking it might be 5* Ranzal fire lance/axe.
For the Gala showcase, I don't think it's gonna be Ramona :l She's pretty niche and I feel like other story characters like Leif, Harle, Zethia, etc will get released first.