I hope this is the right place to ask, basically I need a little feedback/ideas from my fellow sci-fi fans regarding relatively realistic sci-fi weapons (I’m probably going to be asking about others in the future lol)

So, I’m writing a futuristic story but am trying to base it as much as possible in real science that “makes sense” and try to rely on "Sci-Fi magic” as little as I can. For relevant context, this civilization (let’s call it C1 as I am still working on the name) combines “old” and “new” in anything from their ships to their armor in order to be able to deal with any threat they encounter, so C1 uses rail guns as much as plasma cannons, and swords as much as guns.

One thing I want to implement is basically a sword that has lightsaber-like cutting capabilities to deal with superheavy armor but can also clash with other weapons for the mandatory climatic battles. Basically, I want a lightsaber that is not a lightsaber, which would realistically explode or short out when it came in contact with another. I’ve so far settled on using hard light, not quite like in Halo though. I figured that since there have been experiments that have (allegedly) given light some solid-state properties but it is also impossible to actually bend them to a specific shape, I could use a regular sword as "guide" so when turned on the light around the blade would be solidified giving it a hard light coating where the edge would be picometers-thin thus able to cut through matter at a nanomolecular level, effectively cutting through basically anything with relatively little effort BUT when it hits another similar sword, on account of having the same properties they would be unable to cut through each other and would behave like regular swords. Does this make sense? Or how can I adjust my idea to have something similar but without relying entirely on “handwavium”?

Thanks in advance!