with Uranus, Diana's ATK buff would be useless, since they're the same frame/%.
Uranus gives a double ATK combo to all allies, iirc, so she could work better with Sati because of her nice crit buff.
.. also Having Sati and Vishnu gives you 2 2 turn nullifies on girls. (Vishnu also DEF debuffs the enemy on each burst, so more likely to land with Sati's buff too.)
so I suppose Sati would be a better choice...



*sobs in self pride*