making invisible weapons is easier than you think I think. First, you need to decide what model should the invisible weapon have (this is important, since even if you don't see it, the model will affect the damaging the weapon will make and the bounding is really important!). Once you have a good model selected in the databases, export it (with the level editor).
Once you have the model exported, you'll do a trick: open the REO file, and replace ALL the materials to a new texture name, XY.BMP here (for example). Let XY be a 64*64 pure white BPM file (the size and color does not matter, since weapon will be invisible!). Then, make a new BPM file in the same directory, with the name XY_a.bmp (when a texture is [name].BMP, a [name]_a.BMP will be used as [name].BMP's alpha map). So let XY_a.bmp be a pure black texture (so the texture will be 100% transparent due to the pure black alphamap). Import the model back, and voila - you have an invisible model.
Should this not help, I can also send you invisible things. I have many MBs of models here )))
Ah... so *that's* how you do alpha maps in Drakan - that will be useful for future models. (So, technically speaking you could achieve a lightsabre by Alpha-mapping out the blade of a sword and adding a stationary ice effect to it)