So, I'm a big fan of Soul Calibur, and in Soul Calibur there is a character called Cervantes who wields a longsword and pistol sword, the latter having a short barreled firearm protruding perpendicular from the tsuba. I have always wondered what a lightsaber variant would look like, and I decided to use a lightsaber building program and MS paint to make both a Soul Calibur inspired and a Final Fantasy inspired (barrel parallel to blade) "blast-saber" concepts:
I know I have zero art skills, and I'm not really sure how a prop version would function, but here is how I think it might look like.

The names were just heavily shortened from the words "Parallel" and "Perpendicular" referring the barrels orientation to the hilt.