Okay here's one; the Hone Hone no Mi (Lit. Bone Bone Fruit), Paramecia. This devil fruit allows the user to form an exoskeleton for physical protection (like an insect), can form bones into weapons or objects (like cages, shields, etc.) Or even form bones into a giant bone monster. All in all I was somewhat inspired by Naruto's Kimimaro, but I guess the Bone Bone Fruit would be more flexible than Kimi's kekkai-genkai, because instead of ripping out your actual bones from your body you replicate them and keep the originals intact. You could probably even build a house made of bone if you had the Hone Hone no Mi
