I would suggest you try to trade that epic sword for an epic dagger, then get a shield instead. The extra attack speed using a dagger will more than make up the damage from going dual wield - especially when comboing. 50% block rate at lvl 7 bless shield (40% at 6) can't be understated.
Try getting an opaniel shield if you can. You can add 20% melee / 20% damage drop into it. You can do this with a transcended darkness onyx shield too but the extra 5% pvp 10%+ skill defense an opaniel shield gives helps loads - take this from me, one of the most tanky people in the game.
I've tried dual wield. I used to be dual wield. Trust me, it isn't worth it. Bonus points you don't have to spend extra RP for 2 weapons. If you have enough money for both an epic sword and dagger, get an upgrade 2.0 dagger instead. They go for 30-40k. You might have to dual log a rumir to help you survive in maps though. But all the benefits of using a sword (extra damage, extra DD from dual-wielding) go out the window the second you add melee and DD into an opaniel shield.
If you have any guardian-related questions, feel free to pm me in-game.