Like
this or
this?...but with a daedric katana? Should be very simple to do.
If you have
Apophis: Armory of the Silver Dragon, you have the option of using the reversed blue flame or the normal orange/yellow flame that was ripped from a torch. Simply take the NIF from my mod, open it in NIFSkope, open a new NifSkope window and load a daedric katana, Copy Branch the katana and Paste Branch the katana into my NIF (at the root NiNode. Delete my sword's NiTriStrip branch(es), save the NIF as your own weapon and you're done.
NOTE: If you intend on releasing it, you'll need to copy the fire images to a different location and update the texture paths in the NIF to use the new path to keep it from being incompatible with the original mod. If you are keeping this for yourself, then you do not have to mess with it...just know that the graphics will be dependent upon that mod being installed from that point forward.
LHammonds