The Roki Roki no Mi is a Paramecia type Devil Fruit that allows the user to create and control microcrystalline wax. The user also has minimal creation and control over fire and making the user an Candelabra Human. This is said to be the superior counterpart of the Doru Doru no Mi, which also allows the user to create and control paraffin (probably) wax.
Strengths and Weaknesses
Unlike the Doru Doru no Mi, Comet can create wax from any part of his body, being able to make quick armor at any given time. He can also create small amounts of fire, and just enough to make fireballs. Comet's wax is also harder when cooled and has a higher melting point. Because of Comet's ability to create and control fire too, he can imbue his wax with fire and create flaming globs that can be deadly.
Comet is weak when it comes to high temperatures. This is because his wax melts easily at high temperatures, ruining the entire hardness aspect of his wax, which is what he relies on many times. Comet is also weak when it comes to flight. He can fly using wax propulsion, but it is inefficient, taking up large amounts of wax (Comet is unable to create enough fire to propel himself). Because of this, Comet uses this only for combat. Comet also loses energy as he creates more fire and wax.