The way you describe looks structurally impossible based on that image. I can kind of imagine what you're thinking, and I don't think it's possible with the way you drew it.
The key to drawing transforming weapons is to draw tell-tale signs of how the weapon transforms, your weapon is drawn thick, curved, and thus inflexible so it is impossible to visualize the way you described based on that image. For instance, Ruby's scythe is largely folding, so there are a lot of bolts and screws on many of the parts, mostly around the blade where it folds out into the scythe blade, while the shaft and sniper barrel appears to be a slide-out type.
Of course they don't have to be easy to explain or even possible, so long as it is easy to visualize, like Coco's minigun/bag.
Being able to visualize it is the most important part, not just easy for you to visualize, but for others too. Because we can't exactly animate these things.
As I had said before, certain details had been left out due to the scanner scanning the image too powerfully. I did say that most of the functions within the weapon are foldable. The curved parts of the weapon contain very small tubes that twist and turn, allowing the weapon to be more versatile. It may not turn into everything, but it can turn into a lot of things.
One of the weapon's uniquenesses is that the curved functions of the weapon can fold up like a cardboard box. It has limits on how much it could change, but it has enough flexibility to have the weapon to transform into unlikely shapes. Not everything curved stays outside the weapon; there will be times where curved parts of the blade will be used to trigger large firearms and the sorts.
I think I'm not explaining this well because my English is not that good, and I probably need to draw out a sketch of how the weapon works. I have tested it out and formed all kinds of shapes using the parts of the weapons displayed in the image, but I actually forgot how to describe it because the explanation would basically be the size of two persuasive essays (thankfully without MLA citations xD). I will explain it later, though honestly, I do not think this is much of an issue since the character himself was scratched from this particular roleplay by myself.
Captain Uni
Finetales
Plank Sinatra