As of DT they are:
Pld, Drk (its complicated)
Drg, smn,
And her unique job, which is a dual sword style similar to viper, but is based on her affinity with time through her echo. Functions the same ish.

Yūna has a very Agressively offensive style, Hit hard, hit fast, regardless of the cost, and mainly uses slashing weapons so her stances are always a bit wider than a more precise fighting styke like fencing.
It's always been hard for me to describe fighting styles, so I can try to tell you the vibe? She fights as if every fight could be her last, desperately calculated, using her height and weight, and endurance to her advantage against other humanoid opponents. She is unrelenting and would much rather attack in a fury than leave room to be forced on an offensive unless she wants to be.

She retains a knightly code of honor and sticks to what halonisism teaches on that sort of thing, but is not afraid to stop just above a mercy ruling. The only thing stopping her from being a bit of a dirty fighter /is/ the fact she is Halonic and those teachings do include a code of honor.