Kasai Kasai no Mi is a Paramecia type Devil Fruit, anyone who eats this fruit will become capable of eating fire, when the consumers of this fruit eats fire, it will give them a great boost of energy and also helps them to incredibly excelerate their healing, they also can't be hurt by fire. The consumer can also eat fire and store it up inside his body for future use either to consume it when he needs healing or energy, or it can be used in battle as a weapon by breathing it out.