Ok, I finally figured it out! Here is the tutorial: Ok, So you want to get a critter from thief 1 into thief 2. Here is what you need:
1. Both games installed with a full install on thief 1 and a medium or better on thief 2
2. A zip program(winzip works good)
3. Some basic dromed skills( You must know how to change object properties and such)
4. Schema Files. (If you have T:TDP you need to download them). The thief 2 schema files are in the editor/schema/ directory of the thief 2 cd Number TWO .
5. Quite a bit of free hard drive space! Once you have all that, we can begin. Let's assume that we want to add mages into thief 2(NOTE: You need Thief GOLD for this, although the instructions are the same). Ok now the first thing we are going to do is get the model. Go to your Thief gold\crfs\ directory and open mesh.crf. Extract the following files: Fmage.bin, Fmage.cal, Fmage.e, and Fmage(has no extension) . Make a directory in your thief 2 folder called mesh. Put the fmage files in there. . Now fire up DromEd and create a spellcasting critter, lets say a Mechanist priestess. Edit the properties and go to Shape - Model name. Change it to Fmage . Portalize, do pathfinding etc. Then check it out... Oh no! It looks somthing like this dosent it:

The problem is that the model is missing it's skin! What you need to do is open fmage.bin in notepad. It will look like gibberish, thats normal! Now look at it carefully... near the top there will be a small bit of normal text... in this case it will say 5fire2.gif . Now open the thief gold mesh.crf file again and extract 5fire2.gif. Now make a directory called txt16 in your thief2\mesh\ directory. Put 5fire2.gif in there. Ok now! Go back to dromEd and check out your new fire mage-looking priestess. But we still need the voice! Now this is the tricky part. Here is what you need to do: create the following folders in your thief 2 directory:
/SND/
/SCHEMA/
Extract the following into the SND folder:
1.the complete contents of the thief 2 snd.crf file.(For some bizzare reason, this is only neccesary before the patch)
2.All the mage sound files from thief gold snd.crf (Note... Hold control while selecting in winzip...you can tell if its a mage file by looking at it's directory. If it is mage1 or mage2 then extract it.

MAKE SURE DIRECTORY STRUCTURE IS PRESERVED

. It is very important! Now extract the following files into /SCHEMA/ : The mg1.sch and mg2.sch schemas contained in the schemas zip file which is in the dromed zip file on Thief Gold CD #1.
The whole set of thief2 schemas (Just extract em all).
Now open speech.spc ( You should have extracted it with the thief 2 schemas) in notepad. Take a couple minutes to look at the file, noticing the syntax. Notice how whenever there is a random voice , there is first a voice statement with No Archetype statement, then the actual voices that will be picked follow, with archetype statements using the name of the first voice declared. Here is an example of this:
voice vmechfems //RANDOM FEMALE MECHS [#3-4]
voice vmech3 //mc3 -female
archetype vmechfems
voice vmech4 //mc4 -female
archetype vmechfems
Ok, now keep that window open, but open mg1.sch in notpad also. Look at how the syntax works. The important bit here is the declaration of what the voice name is. Here is a example:
schema_voice vmage1 1 tolevelone Notice how I bolded vmage1 . That is because it is the name of the voice. As you can guess, vmage2 is the name of the other mages voice. Ok, now go back to the speech file, go to the end, and put this in :

voice mages
voice vmage2 //mg2 Mage 2
archetype mages
voice vmage1 //mg1 Mage 1
archetype mages

See how we used the structure of voice declarations and archetype declarations? Now save the speech file(Carefull not to save it as a txt file try putting speech.spc in quotes and selecting "all files" . Now add to the priestess the property speech/voice and type in mages then hit ok.Now enter the command

reload_schemas

. Save your gamesys as somthing diffrent and then do set_gamesys *gamesys name*. Load it up, and you should have a priestess that looks and sounds like a mage. In order to make this fire mage actually shoot fireballs, I suggest you check out The_Thief's guide on creating custom characters. Please reply if you find any inaccuracies with the tutorial . Thanks to the following people, without which this tutorial would not be possible:
d0om
Daveboy
Thumper
Evilspirit(Quoted by Daveboy!)

Everone in the TEG forum!