The Final Fantasy Cloud Buster Fusion Sword is popular because it is a unique and iconic sword from a popular video game series. It is also a very large and impressive sword, which makes it popular for cosplay and display.
Additionally, the Final Fantasy Cloud Buster Fusion Sword is popular because of its segmented blade, which can be dismantled. This makes the sword easier to transport and store, and it also adds to the authenticity of the replica.