We all know that an F5 tornado is the most powerful right. What happen an F10 tornado form?
By definition, a F5 is the highest level of damage a tornado can cause. Unless they redefine this scale and expand the definition to include a F10 level, there will never be a F10 tornado. So your question can not be answered as posted. This scale is not based on the wind speed, but the damage the tornado will leave behind.