Which thermal styling tool is used to air form wet hair while using brushes, combs and fingers to create temporary direction and texture changes?

The blow-dryer is the correct choice as it is specifically designed to air form wet hair, allowing for the use of various tools such as brushes, combs, and fingers to achieve temporary direction and texture changes. When using a blow-dryer, the hot air helps to evaporate moisture from the hair, while simultaneously styling it into the desired shape. The technique often involves manipulating the hair with other tools to create volume, curls, or straightness, depending on the desired outcome.

In contrast, a flat iron is primarily used for straightening hair by applying high heat directly to the hair strands. Hot rollers are used to set curls and can also contribute to volume but do not involve the air forming of wet hair. A diffuser is an attachment for a blow-dryer that spreads the airflow, often used to minimize frizz and enhance natural curls, but it does not directly create the styling manipulations that a blow-dryer facilitates with brushes and combs. Hence, the blow-dryer stands out as the tool best suited for air forming and styling wet hair.