Upvote for understanding that proving a negative is a logical fallacy.
On topic, I think it was just a design decision to give Jago a real sword. They have all kinds of lazers and lighting effects for Cinder and Fulgore, so it probably wasn’t a technical issue. In the original KI everything had this sort of “near future” vibe going on and they have definitely moved a little bit away from that - except with Aria’s stage.
Sorry typo there I mnt to say it WASN’T a blade like star-wars.
It’s really just a special kind of blade that only glows when Jago transfers his power into it, and here’s why: In KI1 if you did Thunder’s No-Mercy where he does this ridiculous upper cut into the air on Jago, you’ll see Jago’s sword fallt o the ground, it looks solid and it’s not glowing. If you pull off Jago’s sword stab no mercy in KI2 the sword is clearly not glowing once impaled into the person.
The sword seems to have magic properties. But I do agree with everyone else who says he could use a change of color to the more classic green. That would be nice.