If there was a physical shell filled with plasma, it would be much like an RPG launcher that launched plasma grenades, which incidentally is a weapon I came up with for Lucca. The plasma gun in the original game purported that the projectile itself was made of the substance, which is erroneous. Plasma itself would have a pathetic range, due to its natural state; it's gas that's been ionized by being heated to such temperatures that the electrons are stripped away, and such gas would not stay together. In essence, a plasma gun would be more akin to shooting hot steam at someone.
On Marle's weapons: Those are some pretty awesome names, and they're a lot better than anything I'd come up with. What I'd thought of is a sort of "rail crossbow." Admittedly, though, it'd be hard to best such a weapon, but it is quite likely that Chronopolis possesses such things. There are only two issues with those names: Paris' Bow is unnecessary seeing as Alexandros is already present, and the Fairy Bow has the same name as the one used by Link in Ocarina of Time, which might piss some people off. Ishtar could be replaced by something relating to time.
Well, I'm not sure if you read me 'final' list near the end of my post or not, but I took out all of them I didn't really like, leaving the ones I thought better. Alexandros and Paris I got rid of, though I did like the Fairy Bow one, not knowing it was already in another game. What about Fay Arrow, then? Fay and fairy are essentially the same, after all. And as for Ishtar, hmmm... well, Babylonians would have had no god for time that I know of. One might say KronianBow, as in, to do with Kronos, but he had a sickle, not a bow.
On Lucca's weapons: Because of the presence of Melchior and Belthasar in Chronopolis, Lucca will likely have some very heavy artillery such as high-powered sniper rifles even from the very start of the game. As 2300 A.D. is clearly meant to be futuristic and obviously is three hundred years ahead of us, one would expect the technology to have advanced even beyond our already considerable firearm capabilities. I do like the QuantaShot name, though.
Ah, all right. I had a difficult time with hers, as it is.
On Glenn's weapons: In Scenario 8, the one that introduces the Vanguard and puts Glenn back on the team, Serran gets hold of the Masamune for a limited period of time. When the team retrieves it, its power has been diluted from being in his hands. This would allow for other weaponry such as that which you suggested, because Gram, Durandal, and a dwarven sword are just too good to pass up. At the end, though, he would acquire a supremely powerful version of the Masamune. This would make sense seeing as it's already the best weapon when you get it in Cross.
Well, as I said in my last preamble, I actually don't like the idea of true mythological weapons, in the off chance that they've already been used (and the neccessary explanation of how they found their way into the Chrono world.) Caliburn is the only one I think should be considered, as it is so unknown.
On Magus' weapons: Why not give them all mythological names? Thanatos, Erebos, and such are good, but there are a bunch of mighty warriors and evil spirits out there. Why not Astaroth, or some crazy war god from Japan?
Well, let's see what I can think of as far as evil and nasty things from myth... Thanatos and Erebos as I mentioned, Charon, Typhoeus, Hekate, Eris... though come to think of what you said, lesser things might be better. A general type of thing, rather than a name proper. Like 'Gorgon' (though that's a stupid one). Oh, and I don't off hand know any Japanese war gods. All I know are... what are they called, Inzanami and Inzagami, Ameteratsu, and a few things like that.
On Crono's weapons: I'd avoid using mithril, namely because every RPG and its grandma has that. His weapons are mostly Eastern in their style, but that didn't stop them from making Masamune a broadsword. He has to restock something after they go through the time warp that takes away all their awesome weapons from CT, and since he's in Chronopolis it's going to be something technological. After that, we can move on to Jade Hilt and other things.
Well, as I said, not one in one hundred people will know that Truesilver is mithril, guarenteed. The silver ties in with Chrono Cross, a little, but does not directly reference mithril. And I think Truesilver has a neat ring to it.
Oh, and the Masamune is not a broadsword. It is a two-handed sword, a greatsword, or whatever... but not a broadsword.
I'll try to think of some more weapons. In light of what's been said, I would say of my previous list the ones that could for now be still considered are:
Yew Bow, Apollon or FarShooter, Fay Arrow, Ivory Bow, QuantaShot, SnipeShot, ArmingEdge, Gilt Sword, DwarfSword, Erebos, Jade Hilt, and Truesilver.
How does that sound? That's only... four for Marle, two for Lucca, three for Glenn, one for Magus, and two for Crono.
