I had this idea, that is so absurd to make that I doubt anyone ever will (and I have no idea even how to make a normal weapon...)
I present, "The Eraser"
What "The Eraser" do? It erases targets, literally.
Actual combat effects:
Anything (including wrecks, asteroids, nebulas and control points) touching its main radius, gets erased from the map, immediately.
Erased ships (including ones turned into wrecks first) don't give any salvage or loot, and can't be boarded.
Starting from the "erase radius", ships get damaged, but the further it is, the less the damage is, point blank the damage is enough to insta-kill a unshielded (but still armoured) onslaught.
Campaign effects:
Anyone on the receiving side of a Eraser get relations set to -100 immediately.
Anyone on YOUR side, get -5 relations.
Everyone else decrease relations proportial to how much they are neutral to you or not (0 relations, lose 10 of relation, 100, or -100 relation, lose 50 of relation).
The reason why people hate its use, is because The Eraser actually damages the space itself, ripping it apart and erasing (or shifting to somewhere else, noone is sure), this causes a new jump point to be created, this jump point is unstable, you can use it from both directions (to come, or go to hyperspace), but require navigation skill 10.
If you created the jump from FROM the hyperspace (ie: the battle was there), the endpoint of the jump point is literally, random (thus a battle near Askonia can create a jump to Corvus).