Generally few authors understand the actual motivation or challenges of dual wielding, and that's why I roll my eyes when I see it.
You basically have to be ambidextrous to really be good at it right away, and if not then it takes a lot of practice to do it properly without cutting yourself. There's a reason that when you see dual wielding in historic settings, they usually have one weapon to the side or behind them with their dominant hand outward.
For example I've seen one story describe dual wielding as "pure dedication to offense only" and that was something the mc supposedly learned from a 'dual wielding expert'.
The trick of dual wielding is NOT that you have two swords to attack or block with, it's that you can attack and defend at the same time!
If you're going to cross parry you might as well just have one sword, because the point is to deflect it with one sword and attack with the other at the same time.
Similarly, if you're going to attack with both swords at once as if to 'overpower' the opponent, give up on wielding two weapons.
Not only does attacking with both weapons at once leave you vulnerable, but if you don't even bother to aim for different targets with each sword then it's not even harder to block in any way. (Cross swings are stupid too! Unless just for some magic activation or something)
If you really are transcendental with swords, I can see how it might benefit to dual wield if you're surrounded and outnumbered by enemies, and that would actually look cool, unlike a character that's forced to use dual swords incorrectly just because it looks cool.
Realistically, if you have dual swords, you would be holding one over your shoulder, hanging below your main sword, or otherwise out of the way.
Since the idea is to have one sword block and attack with the other while their weapon is busy.
However if you were to naively just hold both swords out in normal guard positions, they can simply push one of your swords into the other and enter a bind with both of your swords, completely negating your advantage. (Another reason crossing your swords is stupid, entering a bind with both of your weapons is exactly what you want to avoid! (Unless they have something really heavy that you can't block with a single sword and you have to completely stop the attack instead of deflecting it away) (Also, specifically binds where you don't have the advantage, if you're the one binding them, then you can probably easily take one of your swords away from the bind to attack with assuming they are dumb enough not to disengage as soon as it gets to that point. But if you suck they can easily turn your advantageous bind into being in their favor instead))
