Tony Stark is a ridiculously smart guy. If anyone could make a working lightsaber, it would be him. If he designed one, our guess is that he would be arrogant enough to give it his signature style and fashion it after Iron Man’s armor. That means it might look something like this impressive design by The Custom Saber forum user eastern57. The hilt has an arc reactor (of course), and a nice pull apart section. I could see this interpretation being extended to different types of armor, and I hope the artist makes more!
You must check out more photos and a video after the break.