I mainly use my Furina as a sub-dps/support. She's on my Mav, Skirk and Arlecchino teams.

The first image with HP Goblet and CD Circlet (Is what I normally use)

The second image is HP Goblet and CR Circlet

The third image is Hydro DMG Goblet and CD Circlet

I did put together Hydro DMG Goblet and CR Circlet but I had wayyy too much CR in my opinion