Doesn't really matter. In EU, Ventress and Grievous, along with Sora Bulq made the most out of multiple sabers, but Anakin in AOTC got thrashed when he tried it against single-sabered Dooku. It all depends on the skill of theuser.
No of course it doesn't make her all powerful. However she is quite good with them and Luke has never faced anybody that uses lightsabers like that. It would give him an harder time.
True, but if he fared pretty well against Vader in ESB (I know, the Sith Lord wanted to turn him), he could probably manage against Serra. Vader beat Serra by choking her with one hand; Luke fared pretty good against him.
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Well, Luke wouldn't be able to choke her, so that's out. I still believe that Luke would lose. Why? Cuz Serra is the complete opposite of the only other lightsaber wielder he faced, which is Vader. Vader used strong attacks, which for a young person like Luke would be easy to block. But Serra would be a whole lot more agile, with more direct attacks, instead of just powerful ones. Luke would have to transition completely for him to win this, and I don't believe he would be able to.
Remember in ROTJ, when Luke completely overwhelmed Vader with those fast and strong Djem So swings? That's what he'd do to Serra. I mean with two lightsabers, she can attack faster than he can, but her defense is a hell of a lot weaker. Vader, with all of his superhuman strength, was unable to stop Luke's Force powered strikes. Serra would need to use both sabers just to block, and even then, she'd have to be leaping out of the way of his strikes. She'd probably get some kicks and wounds in, but not much else.
Wait, Luke could force power his attacks? When did he do that? If Luke who got almost no training could do that, then ?I think Serra could do that too.
HimoKun- Every single character in Star Wars uses a lightsaber, or throws or punches or jumps or whatever who has control over the Force uses it. In AOTC when Obi Wan throws the homing device at Slave I, he uses the Force unknowingly, just as an instinct. In ROTJ, when Luke throws the skull at the door panel in Jabba's Palace, he uses the Force Do you honestly think Luke could overwhelm Vader with sheer physical power? The dark side powered his strikes. And yes, Serra could do it too, but it would not be as effective, as she'd have to contend with Luke's power as well.
And thats where I think you are mistaking, like you said yourself the Dark Side makes him more powerful. But Luke would not go dark when fighting Serra. He would have no reason to do so, which would remove the only advantage he could possibly get in the fight.
True, but we do know Luke Skywalker is an extremly fast learner. And in EU he learned to deflect Force Lightning as a Jedi Knight...we have no idea of what he learned as a Jedi Knight.