Decide the fate of my Celica!

Salvage, she's going to be a bonus unit for the next two weeks of arena + you can just put Spd+3 SS on her to counter her Bane

Build her on a budget for the sake of arena unless you have another bonus unit. That said, after that go for Chill Speed on Azura for a free debuff at the cost of essentially no B slot since Azura's only going to dance for the most part anyway.