Griever

[JunseiKei]

It has a revolver chamber, a sword grip, and a trigger. If you go forward a few seconds, you can see that it has a barrel mimicking the Garlean standard issue gunblades- only on one side, and notably shorter than the blade. We've also only seen two types of gunblade in XIV, those being the standard issue model that Heirsbane uses(Model IX in the JP version, I think?) and the custom one Regula had. The other hybrid weapons we've seen have been tonfas, shields, and a lance.

Zenos strictly uses katanas after having gained an appreciation of them during his subjugation of Doma. We still don't know what the weird drum sheathe does if it does anything at all. The Ala Mhigo fight makes it seem like it just charges the holstered swords with aether.

Yeah, we don't know what the giant sheaths are for Zenos's swords and that you can see the barrel-like design, but that doesn't necessarily mean it actually does anything other than hold the swords.

We've also seen a gunhammer wielded by Nero in regard to other gunfusion weapons. However, due to the varying types of weapons fused, being of all types of sizes, I don't really see the reason of pointing out the sword Thancred has is different. It makes sense in size if gunblade is actually a tank class as rumored (ugh, I hope not, but it probably will be with my luck; all sword classes are tanks with exception being samurai). Even then, it still falls in line with Squall's gunblade in size comparison.

Also, only one side? I don't understand that part of your comment. Garlean gunweapons seem to be based off of revolvers, which the barrel is seen on both sides of the weapon.