This is an updated version of my take on the Balor Megabeast. I've changed around its body parts and materials such that engaging one in melee is now merely extremely foolhardy, rather than completely suicidal. In addition, it now drops a masterwork vorpal sword after being killed. In addition to the sword being a fine weapon, I've added a few reactions at the smelter that use the sword to fuse rocks into various materials that you may or may not have easy access to. These reactions exercise the sword skill, so they're handy even if you don't need the products.

I've included three versions of the mod files in the download. The "balorog default" version is compatible with any mod which doesn't already have a BALOR_DETAILED creature. Just copy and paste the files found in the mod into your raw directory and add the following lines to the dwarf entity to activate the new reactions:
The other two versions of the mod files are for use with the genesis mod. The files in "balor genesis tiles" are for the graphical version, and the files in "balor genesis ascii" are for use with the ASCII version. You will be prompted to overwrite files when copying these into the genesis mod raw folder, these files were made from the .12 version of the genesis mod so it should be ok. You will still need to add the above code to the dwarf entity, of course.