Download the x_voice update: http://marvelmods.com/forum/index.php/topic,2924.0.html
Emma's voices are there, this might solve the problem (it worked for me)
Thank you, that's indeed the solution, the mod requires that file for her voice

And now...
The Four NPC Beta V0.5
This mod includes:Polaris, Quicksilver, Emma Frost and Sabretooth NPCs for the last battle against Apocalypse and all the
files needed: effects, edited maps, scripts, sounds and more.
Known bugs:
- The effecs may dissapear because XML2 limited memory, so for example Emma's skulls for "Telepathic Illusions"
could be small or just don't appear at all.
- When you beat Apocalypse instead of one of this Four mutants, he doesn't revive using the life from the minion with more health.
This is because XML2 limited memory is not loading the script needed (this bug just happened once)
Aside from the effects and that issue with the fight, the NPCs works fine.
Linkhttp://www.mediafire.com/?pz9rff3b79j16cbThanks to
Raven/Vicarious Vision (Game, original files, effects from MUA/MUA2/XML2)
Nodoubt_jr (Some codes and effects from Quicksilver, for testing the mod and all the answers to my questions

)
Matt710 (Polaris mod and effects)
I'm not sure if I'll update this again since the main problems are because XML2 limited memory and not because the gameplay.
My favorites are Emma and Polaris, those girls always kick my a$$ and you'll see why

I also released updated versions for my mods, details on the first page, but one of the new features is...

A quick reskin.... not the cape that we would like but it looks much better than I thought
