Try to break its combo at the very start then plan Field of Execration in the game
The thing that you must always put in mind is to never give LastChaos Gold them a chance to get near you nor never give them a chance to LURE you into a tight space.
Once you cast Execration>Darkness>Hard luck > Cannon Spam its over for them in just the use of only execration, but if you can penetrate properly their armor then Field of Execration will finish the job.
Sword Style: Hybrid Force Blader using Sword Style with sword Gears is the most effective style in terms of PVP vs FA, its also very effective in MWAR since you are after a Large amount of damage delivery that could effect on a large Area (AOE: Area of effect) and Dungeon due to the same reason.
Versus Force Archer: I would only prefer this style against Force Archers, Again we are expecting for the worst, If they are PVP wise they are equipped with the most effective anti-mana freeze gears and have a different combo set reserved for FB with 4 skill range 9 and could immediately switch to its original combo set once they FB goes sword style.
If they are covered with a costume epaulet: The most logical thing to do is to have a great distance, try to break its combo at the very start then plan Field of Execration and get some more distance.
