i think the weapons in mk:d are just fine, just need more moves is all.
of course kori blade is not a real weapon, unless you could find a giant, sword shaped ice tray then go for it.
a kriss i do believe is real, i have seen a sword once that was shaped exactly like ashrah's kriss.
ermac's axe i think is actually cool, it seems to fit him in my opinion, since axe's seem more of a powerful, inforceful weapon, as is ermac.
if they would just do something simple, like having every weapon having atleast five-ten combos and twenty-five moves (since they can do it with four attack buttons + four directional buttons + normal hits = twenty-five), and they could aswell have the same for each style, then they could really be in buisness.

Ninja's normally have katana blades. I think Kori Blade looks silly and Sub-Zero deserves better...
btw I also hate his ALT ( he should not be depicted as bald )

I like Sub-Zero's Kori Blade, it's a weapon he made himself out of ice. Frost (MK:DA) was able to do similar but because she isn't as powerful or experienced she was only able to make a pair of daggers.
But I agree that Sub-Zero's alternate costume does suck.

Actually ninjas rarely used katanas. They used similar weapons that were shorter and had a straight blade. Check my various fighting styles thread, it's there with the full evolution of japanese swords.
Kriss is an acvtual existing weapon. It is called the maltan kriss. It also has a flame-like edge.
The thoraxe is just the ripoff of a broadaxe. They were used by the nor-manns in the middle ages. Altough it fits Ermac pretty much: a paradox weapon for a paradox fighter.