I have a Dahlia on my Nutaku account. Her skillset is good so any girl close to that you like should be good.
I personally like Dahlia's battle skill animation a lot.
I am looking at Apple, Aloe, Laurentia, Flamingo Plant (Justica), and Dogwood (Yukata).
I am leaning towards Lauerntia or Aloe because Lily of the Valley, Alium, Gerbera, and Glory of the Sun work with Solar drive.
I got a Gerbera x2 (Lv.2 skill, two equip slots), Glory of the Sun (Leucocoryne), and Alium along with a gaggle of 4*s (including 3 more Di Yu) since the last time I mentioned what 5* I have gotten.
Lots of +x% attack but I need to bloom most of my 5* to get at it.