The Rivals gunblade appears to be based on the gunblade from Final Fantasy , which is a fantasy-style hybrid of a sword and firearm.

Real-world inspiration

A real-world weapon often linked to that idea is the pistol sword or gun-sword , which combines a blade with a small gun mechanism.

That makes the Rivals version look like it borrows the concept of a blade- and-gun hybrid, rather than copying a single historical weapon exactly.

In plain terms

  • Main source: Final Fantasy’s gunblade design.
  • Real-life analogue: pistol swords / gun-swords.
  • What it’s not: a standard military weapon; it’s mostly a stylized game weapon inspired by fiction and historical hybrids.

TL;DR: the Rivals gunblade is most likely inspired by Final Fantasy’s gunblade , with a real-world echo in the old pistol sword idea.