Whether consuming protein powder breaks a fast depends on the definition and purpose of the fast. If a fast is defined as a period of time during which an individual abstains from eating solid food and restricts calorie intake, then consuming protein powder would break the fast as it provides calories.
However, if the fast is focused on avoiding specific macronutrients such as carbohydrates and fats, but not protein, then consuming protein powder would not break the fast.
Ultimately, the answer to this question depends on the individual's specific fast and their goals.