From the perspective of the five elements mutually reinforcing each other, fire and water are not suitable for combination.
In numerology, everyone has five elements attributes. The five elements produce each other: metal produces water, water produces wood, wood produces fire, fire produces earth, and earth produces metal. The five elements are in conflict with each other: metal defeats wood, wood defeats earth, earth defeats water, water defeats fire, and fire defeats metal. According to this relationship, water and fire restrain each other and cannot balance the five elements and enhance fortune. Instead, they may have adverse effects.
So, from a numerology perspective, the fire-water name combination is not a good one. If both fire and water characters appear in your name, it may have a negative impact on your health and fortune.