Wow I really like the idea of this. It could add alot of depth to the enemys you fight in this game.

Well going with the melee weapon other then sword theme.
How about a short range energy pulse weapon. It doesn't use a blade, only pure energy to damage an enemy at short range.
Or how about a whip? charged with energy it sounds like it could do some damage.
A scythe could be interesting.
The idea of a hammer is not bad. not all hammers are heavy and hard to maneuver. Speaking of hammer it could be possible to have a mace.

There are few things I think that can be added into the game, but I think the game already has lots of useful and unique weapons. Not to mention that you can pick up almost any object including your enemy as a weapon.

Umm I got an even metter idea!
How about fighting with jehuty's legs and fists? think of Rahxephon for example.
Remember that show? And if you haven't, you should. It's like a great ripoff of Evangelion and Zone of The Enders in one awesome creepy twist. Trust me, it's awesome!
Look it up on youtube, Rahxephon.

Me, I like to see a unique sword , knife and brass knuckles.

yeah gundam wing is basically what it should come down to

Scyth, Trident

I wouldn't mind some dragon hands :3