I prefer the name "Viper" instead of something generic as "Blademaster".

Blademaster/Swordmaster only refers to the mastery of sword, Viper has much more references and set better expectations.

In Final Fantasy jobs:
Viper refers to the 2 blades like the fang of a viper, a "viper" is also used to refer to someone who backstab. The animal also perfectly fits an assassin, fast paced job.
Just like how Dragoon is named Dragoon instead of spearmaster as it refers to a culture, a knight related to dragons be it hunting, riding or using their power.
Samurai is named Samurai instead of Swordmaster or "Japanese Swordsman" as it refers to the culture of Samurai.
Machinist isn't named "Gunner" or "Gunslinger" as it refers to the use of machines rather than the gun.

On the opposite, Fire Emblem swordmaster:
In the whole series, you have Stefan, Lucia Catherine, Rutger, Ryoma. Those characters have way different background and culture.
"Swordmaster" fits an Asian sword user as well a Western sword user. It would fit PLD or SAM if applied to FF.

The name of "Viper" gives far more information and set clear expectations on the job than "dude who's good with swords".