ZDoom

Perhaps I should rephrase this. I'm hoping that there's a way to bake lighting into the voxel, else I'll have to draw the shading by hand, which I've tried and it doesn't look good.

Cherno wrote: If there are several free voxel editors (such as MagicaVoxel) available, why are you using Blender?
If you want to use Blender, why do you convert the models to voxels at all, if model support in GZDoom is superior in every way?

I've used blender so I could get a smooth animation and voxels just fit into the style of Doom better. I'm considering using a sprite instead despite that it will have no depth.

A voxel model only stores color information for each voxel, not per face. That means that you won't be able to retain this information when converting to a voxel file format.
That being said, I am not sure if I understand your problem completely.
If there are several free voxel editors (such as MagicaVoxel) available, why are you using Blender?
If you want to use Blender, why do you convert the models to voxels at all, if model support in GZDoom is superior in every way?

Edit: Or are we talking about some kind of "voxelizer" here which takes normal models and presses them into the blocky voxel look? If so, you have a few options, none of which are perfect. You could select all faces for each of the six directions (up,down,left,right, forward,backward) and uv map them as per your liking. You could also check out my SunSim shader for the quick & dirty approach.

Long story short, there's a way to convert blender models to voxel, and it works quite well. the only downside is that it removes all color, and thus shading, from the model causing it to look flat in game. I was hoping if someone who's far more familiar with voxel editing could fix this. Any help is appreciated.

EDIT: Turns out that SLAB6 is able to burn shading into voxels.