Seeing as that last was pretty much a blatant Star Wars reference, I feel the urge to point out that a thermal sword is not, actually, the local lightsaber equivalent.
It’s a short one of these with a hilt stuck on it.
Which is to say, it’s the exact opposite of a more elegant weapon for a more civilized age; it’s an ugly-ass weapon that’s precisely what you would expect the denizens to cobble together from wreckyard salvage down at your local wretched hive of scum and villainy.
(Also, given the somewhat harder universe parameters, even if it were possible to solve the many and varied physical, engineering, and practical problems involved in waving about a hand-held magnetic bottle of plasma at all, the laws of narrative integrity would require that you die a horrible, fiery death on first encountering an enemy with magnets…
…how do they work?)