Tempered Portent

You are now so deeply connected to the thread of fate that you are able to temper with it. 

If you have at least one Portent d20 left, for the duration of the spell you can increase or decrease its value in up to 2. This change acts as an alteration of the die and not as a bonus, making it possible to turn an 18 roll into a natural 20 and a 3 roll into a natural 1. This spell can only affect one portent d20.