Winter Cecilia (Enemy Phase Build) help

Hello everyone, hope you all are having a great holdiays. This time i've come with a question for a W. Cecilia enemy phase build that'll be good for general use as she'll likely be on mixe emblem teams. My issue is what to do with her C slot & Seal slot as im not too sure to put i these slots. I do have attack smoke for either slot as a option which i think could work out but id still be missing a slot & i want to make sure im not overlooking anything else. Any help would be greatly appreciated. Thank you & happy holidays. The Ceclila will load up if you click on the picture, its showing Catria for some reason.