Can a Head Become an Adventurer?

Bad news: On the first day after transmigrating, Rory got his head chopped off. Good news: As long as his head remained, he could assemble himself endlessly. He woke up in a mass grave, with nothing below his neck. Rory thought he’d landed in a nightmare difficulty setting, until he discovered his newly awakened assembly ability: [Elf left arm] + [Worn wolf-tooth club] = Wolf-Tooth Knuckle Duster with an explosive punch; [Tiefling heart] + [Wooden steam engine model] = Roaring, fire-spewing Infernal Forge Heart; [Human spine] + [Bird feathers] = Bone wings; He could not only detach and reassemble his body at will, but also forcibly fuse supernatural creatures with machinery. Before long, a uniquely bizarre, Legendary amalgamation monster had come into being... [Not an evolution story] [Freeform assembly] [Steampunk]