for element and max damage use umbro MC and fushu for mana, fina Is also a valid option

Depends on the content sorta.As Kielos said, prior to I4 you wanna use Fushu on the team. After I4 you can switch it up a bit.
Fina - Truffle works well for Ensemble because Resolve is highly beneficial there. You can also run Decay on your Calamity Rifle and Truffle gives you full benefit then too.
Fina - UmbroMC works well outside of Ensemble and for a more morale based build set. Also is easier to build up than Truffle since you can get I6 UmbroMC without spending SLC's for it.

Fina and Fushu, and once you have her intron lvl 4 with a maxed out wing inspo huntdown, you can replace Fushu with Truffle with adjustments to Flodia's build.