Yandao, you have three Brandishes? How about turning them into Acheron (a great shadow sword), Combuster (a great elemental sword with high damage), and either Voltedge or Glacius (another elemental sword, for FSC, where Combuster is less useful)?
The main consideration in choosing a sword or gun is damage type. You want to own a piercing sword, an elemental sword, and a shadow sword.
honestly they are all good, fire does more damage (which charge) due to fireness, freeze has more controll cus of freeze (though geting frozen can stop them from riding the explosions), and shock is in between.
Its realy a matter of preference.