Fujin - Shadow (Hyou) : Taciturn.

Being a ninja/assasin type, Shadow rarely speaks and didn't get involved that much in the party affairs.

Fujin prefers efficiency for her speech manner. in Japanese, her dialogue text is shown in kanji while in English is all capitalized word.

Sherlotta - Cait Sith (Crystal Dice) : 🐱 CATS. Their current form are not their real form.

Sherlotta's real form is asleep in the Tower but her consciousness possess an immortal cat. Cait Sith is a cat robot controlled by Reeve.

Reno - Quistis (Galvanic Chain) : Both work for an organization and takes their job with pride.

Reno is an agent and second in command of Turks, an elite investigation department of Shinra. Despite his appearance and laid-back personality when it comes to mission, he always took it professionally.

Quistis is a member of SeeD, a hired mercenary force from Balamb Garden. Despite her lack in leadership, she is proud and always tries her best with her job. When Squall is promoted as Commander of SeeD, Quistis serves as his assistant along with Xu.

(Paired because of professionalism trait sounds unique and indeed there are some scene where they showed their professionalism but tbh it feels random to me.)

Cloud of Darkness - Exdeath (Void Particle Beam) : Both are the entities who wished to return everything to nothingness. (VOID)

Cloud of Darkness is an entity which appears when the imbalance between Light and Dark occurs. It can be said its the embodiment of Void itself.