Who do I use a 6* generic gem on?

Comments

AA would be my vote. Ghost if you can use her well and like her. I never did get on the Ghost train though.

I also already have a 5* sig 100 Ghost

Tasky

Archangel. Consider Angela if you can 200 sig her and like her "not do anything special" playstyle.

AA is the best option available.

Tigra archangel ghost domino

AA
Ghost
Angela