Here are all the weapons that Musashi uses while in her summer form in FGO.
We start with the foam weapons with the cute tiger charm thing--fun weapons to beat someone up with.
Then we have the weird katana and gun amalgamations--guntanas. Although both looked a bit silly, I actually really like their designs and how the base is different between both of them. These were the only ones that I was originally going to do, but I wasn't about to model a whole jet ski for her NP.
Then we have her final weapon, this weird large blade. I found it bit weird how all the previous weapons were dual-wielded and this was a single handed. Then during her NP she separates, and I thought that was cool and all but it took me a while to realize that she holds on to the blades by the point--where it happens to be double-edged--and that's metal, also the energy sword is cool too. Also animating this version of her NP is a lot easier so I went with it. All in all, I'm a big fan of her design and the variety of weapons on her different ascensions.