Martial Prowess vs Incinerate

[Dyzard]

with martial prowess if you are incinerated is it a defense pool of four or five. the question comes up due to the wording saying instead of rolling dice equal to its defense (which would be x-1 for incinerate) it rolls five defense dice. Or due to timing of defense dice pool where it clumps add and subtract at the same time you get your 5 defense dice then subtract one for incinerate?

[Negoldar]

The first step of generating a pool of defense dice is adding dice to it equal to the appropriate defense stat. Martial Prowess overrides this and sets it to 5. 
The next step is to apply effects that add or subtract dice such as Incinerate. 
In this case she would have 4 dice.