Here's a sketch from a fantasy AU that I play with. I wanted to make the blade on Arlo's gunblade / pokeball launcher / harpoon much bigger (almost twice his height), but I worked with the canvas size, for now. Consider that the pocket version. I'll elaborate more another day.
For Candela's harpoon:
Candela has a simple weapon because she can do more with it. This checks out with martial arts because the more simple the weapon in the hands of a skilled fighter, the more problems they'll cause for everyone else
For Arlo's...yeah:
Arlo is crazy. Everything is going to be crazy, and the worst part about his crazy is that his shit is probably going to actually work, as long as he isn't so crazy that it doesn't work. It isn't impressive that it cost an entire country's GDP to design; it's impressive that he didn't kill himself during the testing phase.