So how practical would a transforming Melee weapon (i.e. Bloodborne) be? And in case you don’t know, I means specifically something that can switch between a closer, faster attack and a longer, slower attack.
The idea of a slow heavy attacks is a video game concept. In real combat, dealing with real people, large ponderous strikes are an invitation to be disemboweled.
That said, there is some truth to what Bloodborne does, and it’s worth keeping in mind. Adjusting the way you use your weapon to deal with threats at different ranges is a very real practice. One of the most obvious examples is the practice of pommel bashes with a sword.
A pommel bash is used when you’re too close to use the blade, so instead you’ll simply drive the butt of your sword into your opponent’s face in a downward strike.
Another example is shifting your grip on an axe or polearm. At longer ranges, you benefit from having your grip closer to the butt of the shaft, but in closer combat, you may migrate your hands towards the head, to allow for tighter strike patterns.
This means there’s a few hunters weapons that aren’t something you’d normally want to do, but might work with mythical materials (given you’re reinforcing them with blood stones, the Hunters’ weapons are probably made from something other than conventional materials). This means the telescopic Hunter’s Axe may be a functional option. Normally, you wouldn’t want a telescopic melee weapon, but whatever the thing is constructed from might be hard enough to make this workable.
There’s also a few trick weapons that, might, be viable, if you could actually engineer the things to work. I’m thinking specifically of the Threaded Cane, which transitions from a metal walking stick, into a kind of articulated whip with serrated blades along the cable. There’s basically no way to make one, especially since the core appears to operate “intelligently,” (it has a fixed resting position, unlike a real whip) but it would result in a vicious melee weapon. (In fairness, all of the From games have whips that return to fixed resting positions, so this might not be an intentional function of the Threaded Cane.)
The Moonlight Sword is another example of a weapon that is, basically, viable. It’s a FromSoft standard, and has popped up in every release since Armored Core (I think), but the Bloodborne version is an entirely functional, impossible, weapon. It’s a normal sword, that when transformed creates a magical, energy blade over the physical one. This can be used as a sword, or generate ranged attacks. Like I said, this is entirely viable.
There’s two varieties of trick weapons in Bloodborne that simply don’t work. The hinged ones are, primarily an engineering problem. So, that’s the Saw Cleaver, Saw Spear, and Beasthunter Saif, and probably a few others I’m forgetting. In most cases, the basic design is workable, but the problem is that the hinge would result in a serious structural weakness, rendering the weapon unusable. As with the Hunter’s Axe, this probably isn’t an issue for the specific examples in Bloodborne, but it would be an issue with conventional materials. Also, as with God of War, it’s worth remembering that Bloodborne is a character action game, so the overall scale and proportions would need to be adjusted.
The second are weapons that convert their sheath into another weapon. The Kirkhammer and Ludwig’s Holy Blade both convert this way. The problem is, there’s really no way to make this work. Your character would, effectively, be carrying two weapons. You’d also be be relying on the outer weapon not flying off in combat. Depending on exactly how they lock together, this could be a serious issue.
Ironically, sprinkled through all of this is one real weapon. As in, flat out, “these existed.” The Reiterpallasch is a saber with a mounted firearm. While I’m not sure if any pallasches were fitted with firearms, light blades with attached firearms did see actual use in the 17th and 18th century, particularly in naval boarding actions, where simply having a gun in your hand, in addition to your blade had real utility.
On the whole, sword mounted guns quickly became a historical oddity. They were very situational, and not particularly useful, but they did briefly exist.